CN102632173A - Method for determining thickness-unequal blank for two-dimensional local loading and forming - Google Patents

Abstract

The invention discloses a method for determining a thickness-unequal blank for two-dimensional local loading and forming. In the method disclosed by the invention, an analytical analysis formula is combined based on local loading characteristics, so as to achieve the rapid prediction of material flowing and cavity filling in the two-dimensional forming process of a multi-rib component; the shape of the two-dimensional basic-thickness-unequal blank is rapidly determined through rapidly analyzing the material flowing and cavity filling conditions of the cross section; and then numerical simulation is carried out, the shape of the thickness-unequal blank is modified according to a numerical simulation result under the condition that local leading flowing characteristics are considered; and through zero-time or multiple-time regulation and modification, the final shape of the thickness-unequal blank is obtained. The thickness-unequal blank determined by using the method is reasonable in volume distribution, the defects of insufficient filling, folding and the like in the forming process are eliminated, processing allowance is reduced, foaming load is reduced, the shape of the blank is simple, and the blank is easy to make.

Description

Confirm the not method of uniform thickness blank of two-dimentional local loading and shaping usefulness

Technical field

The hot-working that the present invention relates to the less-deformable alloy in the hot-working field is forged, and specifically is that the gusset class A of geometric unitA local loading and shaping that has two-dimentional deformation behaviour in a kind of definite forming process is used the not method of uniform thickness blank.

Technical background

Adopting the high-performance light alloy material, like titanium alloy and employing lightweight structure, like structures such as thin-walled, integral body, band muscle, is Performance And Reliability, the light-weighted effective technical way of realization equipment that improves parts.Gusset class integrated member with the thin fu jie structure of high muscle has improved structure efficiency effectively, alleviated equipment weight and the military service performance with excellence has been arranged, and is lightweight load-carrying member important in the aerospace flight vehicle.

This type of complex component not only be out of shape but also element structure is complicated by the moulding material difficulty, projected area is big, adopts this class A of geometric unitA of traditional plastic forming process monolithic molding to need huge forcing press, generally exceeds the existing equipment ability.Adopt mould subregion realization local loading and combine isothermal forging can effectively reduce shaping load, expansion capacity of equipment.But because projected area is big and complex structure, forming defectses such as folding, that filling is discontented appear easily in its plastic forming process.Usually flow in order to reduce unhelpful material, blank should approach the forging projection of shape in the floor projection shape.In order to guarantee the die cavity filling, to avoid forming defects, need to change sotck thinkness and distribute simultaneously to obtain preliminary volume distribution.

For the gusset class A of geometric unitA; General its preform blank shape is similar to finish-forging spare; Often the height of finish-forging spare muscle, wide, radius of corner are carried out scaling and confirmed preform blank (work such as T. Altan; Lu Suoyi. modern forging---equipment, material and technology [M]. Beijing: National Defense Industry Press, 1982; J.C.Choi, B.M.Kim, S.W.Kim.Computer-aided design of blockers for rib-web type forging [J] .Journal Materials Processing Technology, 1995,54 (1-4): 314-321).The preform blank shape more complicated that adopts above these methods to obtain near the forging shape, is difficult to be applicable to big, the Plastic Forming of small gusset class A of geometric unitA in batches of size.

For this class A of geometric unitA, adopting simply not, the uniform thickness blank can reduce cost, effectively improve the die cavity filling.People such as Yang He (Sun Nianguang, poplar is closed, Sun Zhichao. and large titanium alloy bulkhead isothermal closed die forging forming technology is optimized [J]. rare metal and engineering, 2009,38 (7): 1296-1300; Z.C.Sun; H.Yang.Forming quality of titanium alloy large-scale integral components isothermal local loading [J] .The Arabian Journal for Science and Engineering; 2009; 34 (1C): 35-45) divide awkward district and the easy district that is shaped of being shaped with member according to filling effect; According to the material volume of different piece design sotck thinkness, this not the uniform thickness blank improved the die cavity filling, but still have the obvious underfill in subregion.(open meeting, Yao Zekun wears bright Zhang Hui etc.; The Guo Hong town. the physical analogy [J] of metal structure ausforming process metal flow rule and filling property. aero-manufacturing technology; 2007, (1): 73-76,91) the Applied Physics simulation experiment method confirmed the whole not uniform thickness blank shape that forges that loads of titanium alloy gusset class A of geometric unitA in " Z " type cross section; But do not consider the local loading characteristic of mould subregion; And long expense of experimental technique cycle is high, particularly for big projected area gusset class integrated member, has limited the application of these class methods.

Zhang Daweis etc. are at Journal Materials Processing Technology the 210th volume; 2 phases; Set up material shunting layer place under the local loading state that the mould subregion causes in the Analysis of local loading forming for titanium-alloy T-shaped components using slab method paper of delivering on the 258-266 page or leaf to the distance calculation formula at muscle die cavity center, following particularly:

Material shunting layer place under under the local loading state that the mould subregion causes to muscle die cavity center apart from x _kAdopt formula (1) to calculate:

$\left\{\begin{array}{cc}{x}_k=\frac{b}{2}& {\mathrm{\σ}}_x{|}_{x=b/2}\≤q\\ x_k=\frac{1}{4}(l+b-\frac{H^2}{\mathrm{mb}})& {\mathrm{\σ}}_x{|}_{x=b/2}>q\end{array}\right.---\left(1\right)$

Wherein:

${\mathrm{\σ}}_x{|}_{x=b/2}=2K+\frac{\mathrm{mK}}{H}(l-b)$

$q=2K(1+\frac{H}{2b})$

In the formula: K is the material shear yield strength; B is that muscle is wide; L is the local loading width; H is the loading zone sotck thinkness; M is the normal shearing friction factor; σ _xDo not flow to the stress of blank X-direction in the web district of muscle die cavity for material, blank contacts with loading upper die and lower die simultaneously in the described web district; Q is the average unit pressure of the X-direction on interior muscle of blank and the web intersection interface, and described muscle and web intersection interface overlap with the muscle cavity lateral.

For improving the die cavity filling, adopt not uniform thickness blank.The surface of said not uniform thickness blank is stepped, and the thickness difference of this ladder is Δ H.But formula (1) is not suitable for the calculating of material shunting layer under the local loading pattern that is caused by this thickness difference.

Summary of the invention

Can not be full of for overcoming the perhaps subregion that exists in the prior art, perhaps not consider the local loading characteristic of mould subregion, perhaps the high deficiency of cost the present invention proposes a kind of definite two-dimentional local loading and shaping and uses the not method of uniform thickness blank.

The gusset class A of geometric unitA local loading and shaping that the present invention proposes confirms to have two-dimentional deformation behaviour comprises the steps: with the method for uniform thickness blank not

Step 1 is simplified the member shape of cross section; Be distributed with the member of rib for upper surface or lower surface, the member cross section is simplifies the cross section; Being distributed with the cross section of rib symmetrically for upper surface and lower surface, when simplifying cross section, serves as to simplify the cross section with the surface of symmetrical center line one side of member thickness direction.And each rib that will simplify in the cross section is designated as i muscle, i=1～n respectively; The rib of simplifying the cross section that is shaped adopts local loading and shaping, and the mould district location is the center of subregion muscle in the loading; Confirm that the arbitrary position in i muscle～i+1 muscle is a district location, described i=1～n-1;

Step 2 is confirmed shunting layer position and muscle die cavity filler volume calculation formula according to the stress state of simplifying in the local loading and shaping of cross section.

Through carrying out the definite required not uniform thickness of the section blank shape of simplifying of rapid analysis realization to simplifying the cross section; To simplifying the cross section when doing rapid analysis, get one not the uniform thickness blank and confirm to simplify the blank shape in cross section according to initial blank as initial blank; Do in the rapid analysis simplifying the cross section, three kinds of local loading states and a kind of whole stress state are arranged; Said three kinds of local loading states are respectively; Because first kind of local loading state that mould part load to form, the second kind of local loading state that forms by the different depth of different webs district mould, and the third local loading state that causes by the step-thickness difference Δ H of the not step-like surface existence of uniform thickness blank; Each is simplified the cross section carry out rapid analysis, set up local rectangular coordinate system at each muscle die cavity place of whole counterdie; The Y coordinate of said local rectangular coordinate system is positioned at the symmetrical centre of muscle die cavity width of living in, and the origin of coordinates of each local rectangular coordinate system is positioned at the intersection point place of this Y coordinate and X coordinate;

First kind of local loading state; The blank lower surface cooperates with bed die; Bottom mold surface has the shaping die cavity of rib; Described first kind of local loading state first muscle die cavity near minute mould position in loading zone arrives between the branch mould position; Blank in this zone contacts with loading upper die and lower die fully, and stress state that at this moment should the zone is first kind of local loading state;

Under first kind of local loading state; The local loading width is and occurs in first kind of local loading state region near first muscle die cavity center of minute mould position to dividing two times of distance between the mould position; Local loading width l does not change in the stage in local loading, and occurring between the same line journey of sotck thinkness H in first kind of local loading state region is linear relationship; Adopt computing formula (1) calculate first kind of local loading state material shunting layer place down arrive muscle die cavity center apart from x _k:

$\left\{\begin{array}{cc}{x}_k=\frac{b}{2}& {\mathrm{\σ}}_x{|}_{x=b/2}\≤q\\ x_k=\frac{1}{4}(l+b-\frac{H^2}{\mathrm{mb}})& {\mathrm{\σ}}_x{|}_{x=b/2}>q\end{array}\right.---\left(1\right)$

Wherein:

${\mathrm{\σ}}_x{|}_{x=b/2}=2K+\frac{\mathrm{mK}}{H}(l-b)$

$q=2K(1+\frac{H}{2b})$

In the formula: K is the material shear yield strength; B is that muscle is wide; L is the local loading width; H is for first kind of local loading state region sotck thinkness occurring; M is the normal shearing friction factor; σ _xDo not flow to the stress of blank X-direction in the web district of muscle die cavity for material, blank contacts with loading upper die and lower die simultaneously in the described web district; Q is the average unit pressure of the X-direction on interior muscle of blank and the web intersection interface, and described muscle and web intersection interface overlap with the muscle cavity lateral; The local coordinate system that is adopted in the formula (1) by simplify blank in the cross section the local coordinate system of inflow muscle die cavity;

Occurring first kind of local loading state region sotck thinkness H in the forming process is confirmed by formula (2) with the relation that loads patrix stroke s:

H＝H ₀-s (2)

In the formula: H ₀For first kind of local loading state region initial blank thickness occurring; S is for loading the patrix stroke;

Flow into the material volume V of muscle die cavity _InConfirm by formula (3):

$V_{\mathrm{in}}={\∫}_{s_1}^{s_2}{x}_k\left(s\right)\mathrm{ds}---\left(3\right)$

Second kind of local loading state; The blank lower surface cooperates with bed die; Bottom mold surface has the shaping die cavity of rib; The both sides web thickness of muscle changes; In loading and shaping; Blank between the adjacent muscle die cavity with a side of this muscle die cavity contacts with loading upper die and lower die fully; And the blank between the adjacent muscle die cavity with opposite side of said this muscle die cavity does not contact with loading upper die and lower die fully, and the stress state between the adjacent muscle die cavity with a said side of said this muscle die cavity this moment is second kind of local loading state;

Under second kind of local loading state; The local loading width is said this muscle cavity lateral two times to distance between the adjacent muscle die cavity of this side center; Local loading width l does not change in the stage in local loading, and occurring between the same line journey of sotck thinkness H in second kind of local loading state region is linear relationship; Said muscle cavity lateral is the sidewall that second kind of local loading state one side appears in this muscle die cavity; Adopt formula (1) calculate second kind of local loading state material shunting layer place down arrive muscle die cavity center apart from x _kH in the formula (1) is for second kind of local loading state region sotck thinkness occurring;

Occurring second kind of local loading state region sotck thinkness H in the forming process is confirmed by formula (2) with the relation that loads patrix stroke s: the H in the formula (2) ₀For second kind of local loading state region initial blank thickness occurring;

Flow into the material volume V of muscle die cavity _InConfirm by formula (3);

The third local loading state; The blank lower surface cooperates with bed die; Bottom mold surface has the shaping die cavity of rib; The surface of said not uniform thickness blank is stepped, and the thickness difference of this ladder is Δ H; Described the third local loading state is between each rib shaping die cavity of bed die; Perhaps between the rib shaping die cavity at member one end proximity head place should the end face madial wall of end to said counterdie, perhaps between each rib shaping die cavity of bed die and the rib shaping die cavity at member one end proximity head place should the end face madial wall of end to said counterdie between; And should contact fully with counterdie by the zone blank, the stress state that this moment should the zone is the third local loading state;

Under the third local loading state; The local loading width is and blank in the third local loading state region occurs with upper die and lower die two times of width of contact portion simultaneously; This local loading width l is dynamic change with loading procedure in local loading in the stage, and occurring between H and the same line journey of Δ H in the third local loading state region is nonlinear correlation; Material shunting layer place under the third local loading state to muscle die cavity center apart from x _kConfirm by formula (4):

$\left\{\begin{array}{cc}{x}_k=\frac{b}{2}& {\mathrm{\σ}}_x{|}_{x=b/2}\≤q\\ x_k=\frac{1}{4}(l+b)-\frac{\mathrm{\ΔH}}{2m}(1+\frac{H+\mathrm{\ΔH}}{2b})& {\mathrm{\σ}}_x{|}_{x=b/2}>q\end{array}\right.---\left(4\right)$

Wherein:

${\mathrm{\σ}}_x{|}_{x=b/2}=\frac{\mathrm{mK}}{\mathrm{\ΔH}}(l-b)$

$q=2K(1+\frac{H+\mathrm{\ΔH}}{2b})$

In the formula: K is the material shear yield strength; B is that muscle is wide; L is the local loading width; Δ H is for becoming the thickness difference of caliper zones; H is for becoming in the caliper zones not with the sotck thinkness that loads upper mould contact; M is the normal shearing friction factor; σ _xDo not flow to the stress of blank X-direction in the web district of muscle die cavity for material, blank contacts with loading upper die and lower die simultaneously in the described web district; Q is the average unit pressure of the X-direction on interior muscle of blank and the web intersection interface, and described muscle and web intersection interface overlap with the muscle cavity lateral; The local coordinate system that is adopted in the formula (4) by simplify blank in the cross section the local coordinate system of inflow muscle die cavity;

In the forming process, the dynamic change of local loading width l is confirmed by formula (5):

l＝l ₀+b ₁s+b ₂s ² (5)

L in the formula ₀Be initial local loading width; S is for loading the patrix stroke; b ₁Be coefficient once; b ₂Be the quadratic term coefficient; b ₁And b ₂Confirm by formula (6) and formula (7) respectively:

ln(b ₁)＝1.16941+0.03880A-0.13668B-0.33010C-0.47077D-0.04376R+0.17274lnA+0.73480lnB-0.39029lnC+0.64892lnR (6)

ln(b ₂)＝-1.01970-0.03751A+0.74384B-0.04876C-0.22359D+1.19454R+0.94165lnA-3.74272lnB-0.45123lnC-1.50094lnR (7)

A is l in the formula ₀The ratio of/b, B are L/l ₀Ratio, C is H ₀The ratio of/b, D are Δ H ₀/ H ₀Ratio; L is muscle die cavity center two times to distance between the restrained end of thickness H biscuit area; R is defined as the ratio of width increment Delta l and thickness difference Δ H for becoming the transition condition of caliper zones, is Δ l/ Δ H;

The thickness difference Δ H that becomes caliper zones in the forming process is confirmed by formula (8):

ΔH＝C ₁-s-H (8)

In the formula: C ₁Be Δ H ₀Add H ₀Sum; Δ H ₀For original depth poor; H ₀For becoming in the caliper zones not with the initial blank thickness that loads upper mould contact;

Order

K ₁＝L-l ₀，

K ₂＝-b ₁C ₁-b+l ₀，

K ₃＝-2(b ₂C ₁-b ₁)，

${\mathrm{<figure-callout\; id="4"\; label="K"\; filenames="HDA0000138839800000012.png,HDA0000138839800000022.png"\; state="\{\{state\}\}">K</figure-callout>}}_4=b_1-\frac{1}{m}-\frac{{\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HDA0000138839800000013.png,HDA0000138839800000021.png"\; state="\{\{state\}\}">C</figure-callout>}}_1}{2\mathrm{mb}},$

${\mathrm{<figure-callout\; id="5"\; label="K"\; filenames="HDA0000138839800000012.png"\; state="\{\{state\}\}">K</figure-callout>}}_5=2b_2+\frac{1}{2\mathrm{mb}},$

$K_6=-C_1{\mathrm{<figure-callout\; id="4"\; label="K"\; filenames="HDA0000138839800000012.png,HDA0000138839800000022.png"\; state="\{\{state\}\}">K</figure-callout>}}_4+\frac{1}{2}(l_0-b),$

$K_7=\frac{{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA0000138839800000013.png,HDA0000138839800000021.png"\; state="\{\{state\}\}">b</figure-callout>}}_1}{2}+K_4-C_1{\mathrm{<figure-callout\; id="5"\; label="K"\; filenames="HDA0000138839800000012.png"\; state="\{\{state\}\}">K</figure-callout>}}_5,$

$K_8={\mathrm{<figure-callout\; id="5"\; label="K"\; filenames="HDA0000138839800000012.png"\; state="\{\{state\}\}">K</figure-callout>}}_5+\frac{{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="HDA0000138839800000012.png,HDA0000138839800000013.png"\; state="\{\{state\}\}">b</figure-callout>}}_2}{2},$

Said K ₁～K ₈Be the simplification item in (9) and the formula (10);

Flow into the material volume V of muscle die cavity _InConfirm by formula (9) or formula (10) differential equation group:

Work as σ _x| _X=b/2Have during≤q: $\left\{\begin{array}{c}(K_1-b_{1}s-b_2{s}^2)\frac{\mathrm{DH}}{\mathrm{Ds}}-({\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA0000138839800000013.png,HDA0000138839800000021.png"\; state="\{\{state\}\}">b</figure-callout>}}_1+2b_{2}s)H={\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="HDA0000138839800000012.png,HDA0000138839800000013.png"\; state="\{\{state\}\}">K</figure-callout>}}_2+K_{3}s+3b_2{s}^2\\ \frac{d{V}_{\mathrm{In}}}{\mathrm{Ds}}=\frac{b}{2}\end{array}\right.---\left(9\right)$

Work as σ _x| _X=b/2Have during＞q: $\left\{\begin{array}{c}(K_1-b_{1}s-b_2{s}^2)\frac{\mathrm{DH}}{\mathrm{Ds}}-({\mathrm{<figure-callout\; id="4"\; label="K"\; filenames="HDA0000138839800000012.png,HDA0000138839800000022.png"\; state="\{\{state\}\}">K</figure-callout>}}_4+K_{5}s)H=K_6+K_{7}s+K_8{s}^2\\ \frac{d{V}_{\mathrm{In}}}{\mathrm{Ds}}=\frac{1}{4}(l_0+b+b_{1}s+b_2{s}^2)-\frac{C_1-s-H}{2m}(1+\frac{C_1-s}{2b})\end{array}\right.---\left(10\right)$

Can find the solution formula (9), formula (10) with numerical method according to initial condition;

Whole stress state; The blank lower surface cooperates with bed die; Bottom mold surface has the shaping die cavity of rib; Described whole stress state is between each rib shaping die cavity of bed die; Perhaps between the rib shaping die cavity at member one end proximity head place should the end face madial wall of end to said counterdie, perhaps between each rib shaping die cavity of bed die and the rib shaping die cavity at member one end proximity head place should the end face madial wall of end to said counterdie between; And should the zone blank contact fully with loading upper die and lower die, the stress state that this moment should the zone is whole stress state;

When the rib shaping die cavity at member one end proximity head place should be whole stress state between end face madial wall of end to said counterdie, then material shunting layer place arrive this rib shaping die cavity center apart from x _kFor said counterdie is somebody's turn to do the distance of the end face madial wall of end to this rib shaping die cavity center;

When being whole stress state between i muscle die cavity and i+1 the muscle die cavity, then material shunting layer place to i muscle die cavity center apart from x _kConfirm by formula (11):

$x_k=\frac{a_{i,i+1}}{2}+\frac{b_i-b_{i+1}}{4}+\frac{{\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="HDA0000138839800000012.png,HDA0000138839800000013.png"\; state="\{\{state\}\}">H</figure-callout>}}^2}{4m}(\frac{1}{b_{i+1}}-\frac{1}{b_i})---\left(11\right)$

In the formula: a _{I, i+1}It is the distance between i muscle die cavity center and i+1 the muscle die cavity center; b _iThe muscle that is i muscle is wide; b _I+1The muscle that is i+1 muscle is wide; H is for whole stress state zone sotck thinkness occurring; M is the normal shearing friction factor;

Occurring whole stress state zone sotck thinkness H in the forming process is confirmed by formula (12) with the relation that loads patrix stroke s:

H＝H ₀-s (12)

In the formula: H ₀For whole stress state zone initial blank thickness occurring; S is for loading the patrix stroke;

Flow into the material volume V of muscle die cavity _InConfirm by formula (13):

$V_{\mathrm{in}}={\&Integral;}_{s_1}^{s_2}{x}_k\left(s\right)\mathrm{ds}---\left(13\right)$

Step 3 is simplified the high analytical Calculation of cross section local loading and shaping process shaping muscle;

First loads the material volume that flows into each muscle die cavity of simplification cross section in the step calculates:

Confirm that first loads the range of patrix, get and calculate step delta s that the span of said Δ s is 0.01～0.1; In step delta s,, confirm to simplify the stress state of i muscle die cavity both sides, cross section, i=1～n according to step 2; Geometric parameter, friction condition according to stress state, muscle die cavity and blank calculate the material volume that flows into i muscle die cavity simplifying the cross section respectively; I muscle die cavity both sides blank do not contact with bed die with mold, and flowing into muscle die cavity material volume is zero; So far accomplish the calculating of a step delta s; The material volume of each muscle die cavity that record obtains upgrades the blank geometric parameter and contacts situation;

According to step 2, repeat said process, continue to confirm the stress state of each muscle die cavity both sides and calculate the material volume that flows into each muscle die cavity; Said continuation is confirmed the stress state of each muscle die cavity both sides and is calculated in the material volume process that flows into each muscle die cavity, and accumulation calculating step delta s until the range of accomplishing the first loading patrix, obtains flowing into the material volume of each muscle die cavity;

After the calculating in the first loading step of completion, on the blank shape basis of subregion shaping rib, the material volume that carries out each muscle die cavity of inflow simplification cross section in the second loading step calculates:

Confirm that second loads the range of patrix, get and calculate step delta s that the span of said Δ s is 0.01～0.1;

In step delta s,, confirm to simplify the stress state of i muscle die cavity both sides, cross section, i=1～n according to step 2; Geometric parameter, friction condition according to stress state, muscle die cavity and blank calculate the material volume that flows into i muscle die cavity simplifying the cross section respectively; I muscle die cavity both sides blank do not contact with bed die with mold, and flowing into muscle die cavity material volume is zero; So far accomplish the calculating of a step delta s; The material volume of each muscle die cavity that record obtains upgrades the blank geometric parameter and contacts situation;

According to step 2, repeat said process, continue to confirm the stress state of each muscle die cavity both sides and calculate the material volume that flows into each muscle die cavity; The stress state and the calculating that continue definite each muscle die cavity both sides flow in the material volume process of each muscle die cavity, and accumulation calculating step delta s until the range of accomplishing the second loading patrix, obtains flowing into the material volume of each muscle die cavity;

Accomplish two calculating that load the step, the high h of shaping muscle that simplifies each muscle in the cross section is confirmed by formula (14) respectively:

$h=\frac{V_{\mathrm{in}}^{\mathrm{tot}}}{b}---\left(14\right)$

Flow into the material volume of muscle die cavity in the formula in

whole forming process;

Step 4 is confirmed basically not uniform thickness blank shape;

I is distributed with the member of rib for upper surface or lower surface:

A. revise not uniform thickness blank based on analysis result, simplify the high analytical Calculation of cross section local loading and shaping process shaping muscle.Revise not uniform thickness blank according to analysis result, and carry out to simplify the high analytical Calculation of cross section local loading and shaping process shaping muscle, when the shaping muscle height that calculates with the difference in height e between the designing requirement muscle height _hMaximum max (e _h) during less than 10-15%, stop to revise blank; Obtain not uniform thickness blank shape

B. be the basis with the not uniform thickness blank shape that obtains, simultaneously based on following principle, adjustment correction becomes the transition condition R of caliper zones:

Become caliper zones transition condition R＞1;

Blank becomes caliper zones and should avoid being arranged near the branch mould position and near the muscle die cavity;

If near muscle die cavity or mould subregion, the change caliper zones is set, need to adopt bigger transition condition, i.e. R＞2;

Obtain the component partial loading and shaping with uniform thickness blank not basically;

II is distributed with the cross section of rib symmetrically for upper surface and lower surface,

A. revise not uniform thickness blank based on analysis result, simplify the high analytical Calculation of cross section local loading and shaping process shaping muscle.Revise not uniform thickness blank according to analysis result, and carry out to simplify the high analytical Calculation of cross section local loading and shaping process shaping muscle, when the shaping muscle height that calculates with the difference in height e between the designing requirement muscle height _hMaximum max (e _h) during less than 10-15%, stop to revise blank; Obtain not uniform thickness blank shape;

B. be the basis with the not uniform thickness blank shape that obtains, revise the transition condition R that becomes caliper zones based on following principle adjustment simultaneously:

Become caliper zones transition condition R＞1;

Blank becomes caliper zones and should avoid being arranged near the branch mould position and near the muscle die cavity;

If near muscle die cavity or mould subregion, the change caliper zones is set, need to adopt bigger transition condition, i.e. R＞2;

Obtain the not uniform thickness blank of member thickness direction center line one side.

The not uniform thickness blank mirror image that c. will obtain makes blank upper surface and the lower surface change caliper zones that distributes symmetrically; Obtain the component partial loading and shaping with uniform thickness blank not basically.

Step 5 is confirmed finally not uniform thickness blank according to the member shape; Confirm not uniform thickness blank through the Computer Numerical Simulation analysis; The forming process of uniform thickness blank not basically in the numerical simulation analysis step 4; First loads the step to the first loading patrix loading, and the second loading step loaded the patrix loading to second; Two load the step back if member shape unmet filling requirement is then revised blank shape according to numerical simulation result, until the not uniform thickness blank that is met the filling requirement.

The present invention is based on the local loading characteristic and combine the analytical analysis computing formula; Realization is to the fast prediction with the die cavity filling that flows of material in the many rib components two dimension forming processes; Flow and die cavity filling situation through the material on the rapid analysis cross section, confirm two dimension uniform thickness blank shape not basically rapidly, carry out numerical simulation then; According to numerical simulation result; And consider the local loading flow performance, and revise not uniform thickness blank shape, obtain final not uniform thickness blank shape through zero degree or adjustment correction repeatedly.The not uniform thickness stock volume that the present invention confirms is distributed rationally, eliminates the defectives such as being not fully filled, folding that exists in the forming process, reduces allowance, reduced shaping load, and blank shape simply is easy to base.

Description of drawings

Fig. 1 is that definite two-dimentional gusset class A of geometric unitA local loading and shaping is used the not flow chart of uniform thickness blank method.

Fig. 2 is different stress state sketch mapes, and wherein, Fig. 2 a is first kind of local loading view; Fig. 2 b is second kind of local loading view; Fig. 2 c is the third local loading view; Fig. 2 d is whole stress state sketch map.

Fig. 3 is that definition becomes caliper zones transition condition sketch map.

Fig. 4 is member shape and the mould district location of embodiment one.

Fig. 5 is the uniform thickness blank shape not basically of embodiment one.

Fig. 6 is the numerical simulator of embodiment one.

Fig. 7 is member shape and the mould district location of embodiment two.

Fig. 8 is the uniform thickness blank shape not basically of embodiment two.

Fig. 9 is the numerical simulator of embodiment two.

Figure 10 is the finally uniform thickness blank shape not of embodiment two.Among the figure,

1. for loading patrix 3., whole counterdie 2. do not load not uniform thickness blank of patrix 4. blanks 5. mould district locations 6. whole counterdies 7. first loading patrixes 8. second loading patrixes 9..

The specific embodiment

Embodiment one:

Present embodiment is that a kind of definite two-dimentional local loading and shaping is used the not method of uniform thickness blank.As shown in Figure 4, the member lower surface of present embodiment has rib; Having six ribs, is that an end of rib begins from the member edge, successively each rib note is made the 1st muscle～the 6th muscle.Patrix is divided into two, and the mould district location is between the 4th muscle and the 5th muscle, and the distance at distance the 4th muscle center is 75% of the 4th muscle center and the 5th a muscle centre distance; The material of member is the Ti-6Al-4V titanium alloy.Forming process in the present embodiment has two and loads the step.

In the present embodiment, gusset class A of geometric unitA local loading and shaping adopts ausforming technology, 950 ℃ of forming temperatures, and patrix loading velocity 1mm/s, getting friction factor m is 0.3.

Concrete confirms that uniform thickness blank shape process is not following:

Step 1 is simplified the member shape of cross section;

Member only lower surface has rib, need not to simplify, and the member cross section is simplifies cross section, cross sectional shape promptly shown in Figure 4;

Simplify the cross section, only lower surface has rib, has six ribs, is that an end of rib begins from the member edge, each muscle is remembered respectively made the 1st muscle～the 6th muscle successively.Patrix is divided into two, and the mould district location is between the 4th muscle and the 5th muscle, and the distance at distance the 4th muscle center is 75% of the 4th muscle center and the 5th a muscle centre distance.

Step 2 is confirmed shunting layer position and muscle die cavity filler volume calculation formula according to the stress state of simplifying in the local loading and shaping of cross section.

In definite shunting layer position and during muscle die cavity filler volume calculation formula, set up local rectangular coordinate system at each muscle die cavity place of whole counterdie 1; The Y coordinate of said local rectangular coordinate system is positioned at the symmetrical centre of muscle die cavity width of living in, and the origin of coordinates of each local rectangular coordinate system is positioned at the intersection point place of this Y coordinate and X coordinate.

The uniform thickness blank is not as initial blank at first to get one, and according to simplifying the required geometry characteristic that does not wait thick stock, mould of section, three kinds of local loading states and a kind of whole stress state appear in meeting in the local loading and shaping process.

First kind of local loading state is shown in Fig. 2 a; The blank lower surface cooperates with bed die.Bottom mold surface has the shaping die cavity of rib.Described first kind of local loading state is positioned at loading zone first muscle die cavity near minute mould position 5, i.e. the 4th muscle die cavity in first local loading step and 5th the muscle die cavity of second local loading in the step are to dividing between the mould position 5; Blank in this zone contacts with loading upper die and lower die fully, and stress state that at this moment should the zone is first kind of local loading state.

Under first kind of local loading state; The local loading width is and occurs in first kind of local loading state region near first muscle die cavity center of minute mould position 5 to dividing two times of distance between the mould position 5; Local loading width l does not change in the stage in local loading, and occurring between the same line journey of sotck thinkness H in first kind of local loading state region is linear relationship.Adopt computing formula (1) calculate first kind of local loading state material shunting layer place down arrive muscle die cavity center apart from x _k:

$\left\{\begin{array}{cc}{x}_k=\frac{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="HDA0000138839800000012.png,HDA0000138839800000013.png"\; state="\{\{state\}\}">b</figure-callout>}}{2}& {\mathrm{\&sigma;}}_x{|}_{x=b/2}\&le;q\\ x_k=\frac{1}{4}(l+b-\frac{{\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="HDA0000138839800000012.png,HDA0000138839800000013.png"\; state="\{\{state\}\}">H</figure-callout>}}^2}{\mathrm{mb}})& {\mathrm{\&sigma;}}_x{|}_{x=b/2}>q\end{array}\right.---\left(1\right)$

Wherein:

${\mathrm{\&sigma;}}_x{|}_{x=b/2}=2K+\frac{\mathrm{mK}}{H}(l-b)$

$q=2K(1+\frac{H}{2b})$

In the formula: K is the material shear yield strength; B is that muscle is wide; L is the local loading width; H is for first kind of local loading state region sotck thinkness occurring; M is the normal shearing friction factor; σ _xDo not flow to the stress of blank X-direction in the web district of muscle die cavity for material, blank contacts with loading upper die and lower die simultaneously in the described web district; Q is the average unit pressure of the X-direction on interior muscle of blank and the web intersection interface, and described muscle and web intersection interface overlap with the muscle cavity lateral.The local coordinate system that is adopted in the formula (1) by simplify blank in the cross section the local coordinate system of inflow muscle die cavity.

Occurring first kind of local loading state region sotck thinkness H in the forming process is confirmed by formula (2) with the relation that loads patrix stroke s:

H＝H ₀-s (2)

In the formula: H ₀, first kind of local loading state region initial blank thickness appears; S loads the patrix stroke;

Flow into the material volume V of muscle die cavity _InConfirm by formula (3):

$V_{\mathrm{in}}={\&Integral;}_{s_1}^{s_2}{x}_k\left(s\right)\mathrm{ds}---\left(3\right)$

Second kind of local loading state is shown in Fig. 2 b; The blank lower surface cooperates with bed die.Bottom mold surface has the shaping die cavity of rib.The 3rd muscle both sides web thickness changes; In second local loading goes on foot; Blank between the 3rd muscle die cavity and the 4th muscle die cavity contacts with loading upper die and lower die fully; And the blank between the 3rd muscle die cavity and the 2nd the muscle die cavity does not contact with loading upper die and lower die fully, and the stress state between this moment the 3rd muscle die cavity and the 4th the muscle die cavity is second kind of local loading state.

Under second kind of local loading state, the local loading width is two times of distance between 3 the muscle cavity lateral in the 4th muscle die cavity center to the, and described the 3rd muscle cavity lateral is the sidewall of the 3rd muscle die cavity and the 4th the adjacent side of muscle die cavity.Local loading width l does not change in the stage in local loading, and occurring between the same line journey of sotck thinkness H in second kind of local loading state region is linear relationship.Adopt computing formula (1) calculate second kind of local loading state material shunting layer place down arrive muscle die cavity center apart from x _k:

$\left\{\begin{array}{cc}{x}_k=\frac{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="HDA0000138839800000012.png,HDA0000138839800000013.png"\; state="\{\{state\}\}">b</figure-callout>}}{2}& {\mathrm{\&sigma;}}_x{|}_{x=b/2}\&le;q\\ x_k=\frac{1}{4}(l+b-\frac{{\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="HDA0000138839800000012.png,HDA0000138839800000013.png"\; state="\{\{state\}\}">H</figure-callout>}}^2}{\mathrm{mb}})& {\mathrm{\&sigma;}}_x{|}_{x=b/2}>q\end{array}\right.---\left(1\right)$

Wherein:

${\mathrm{\&sigma;}}_x{|}_{x=b/2}=2K+\frac{\mathrm{mK}}{H}(l-b)$

$q=2K(1+\frac{H}{2b})$

In the formula: K is the material shear yield strength; B is that muscle is wide; L is the local loading width; H is for second kind of local loading state region sotck thinkness occurring; M is the normal shearing friction factor; σ _xDo not flow to the stress of blank X-direction in the web district of muscle die cavity for material, blank contacts with loading upper die and lower die simultaneously in the described web district; Q is the average unit pressure of the X-direction on interior muscle of blank and the web intersection interface, and described muscle and web intersection interface overlap with the muscle cavity lateral.The local coordinate system that is adopted in the formula (1) by simplify blank in the cross section the local coordinate system of inflow muscle die cavity.

Occurring second kind of local loading state region sotck thinkness H in the forming process is confirmed by formula (2) with the relation that loads patrix stroke s:

H＝H ₀-s (2)

In the formula: H ₀For second kind of local loading state region initial blank thickness occurring; S is for loading the patrix stroke;

Flow into the material volume V of muscle die cavity _InConfirm by formula (3):

$V_{\mathrm{in}}={\&Integral;}_{s_1}^{s_2}{x}_k\left(s\right)\mathrm{ds}---\left(3\right)$

The third local loading state is shown in Fig. 2 c; The blank lower surface cooperates with bed die.Bottom mold surface has the shaping die cavity of rib.The surface of said not uniform thickness blank is stepped, and the thickness difference of this ladder is Δ H.Described the third local loading state is between each rib shaping die cavity of bed die; Perhaps between the rib shaping die cavity at member one end proximity head place should the end face madial wall of end to said counterdie, perhaps between each rib shaping die cavity of bed die and the rib shaping die cavity at member one end proximity head place should the end face madial wall of end to said counterdie between; And should contact fully with counterdie by the zone blank, the stress state that this moment should the zone is the third local loading state.

Under the third local loading state; The local loading width is and blank in the third local loading state region occurs with upper die and lower die two times of width of contact portion simultaneously; This local loading width l is dynamic change with loading procedure in local loading in the stage, and occurring between H and the same line journey of Δ H in the third local loading state region is nonlinear correlation.Material shunting layer place under the third local loading state to muscle die cavity center apart from x _kConfirm by formula (4):

$\left\{\begin{array}{cc}{x}_k=\frac{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="HDA0000138839800000012.png,HDA0000138839800000013.png"\; state="\{\{state\}\}">b</figure-callout>}}{2}& {\mathrm{\&sigma;}}_x{|}_{x=b/2}\&le;q\\ x_k=\frac{1}{4}(l+b)-\frac{\mathrm{\&Delta;H}}{2m}(1+\frac{H+\mathrm{\&Delta;H}}{2b})& {\mathrm{\&sigma;}}_x{|}_{x=b/2}>q\end{array}\right.---\left(4\right)$

Wherein:

${\mathrm{\&sigma;}}_x{|}_{x=b/2}=\frac{\mathrm{mK}}{\mathrm{\&Delta;H}}(l-b)$

$q=2K(1+\frac{H+\mathrm{\&Delta;H}}{2b})$

In the formula: K is the material shear yield strength; B is that muscle is wide; L is the local loading width; Δ H is for becoming the thickness difference of caliper zones; H is for becoming in the caliper zones not with the sotck thinkness that loads upper mould contact; M is the normal shearing friction factor; σ _xDo not flow to the stress of blank X-direction in the web district of muscle die cavity for material, blank contacts with loading upper die and lower die simultaneously in the described web district; Q is the average unit pressure of the X-direction on interior muscle of blank and the web intersection interface, and described muscle and web intersection interface overlap with the muscle cavity lateral.The local coordinate system that is adopted in the formula (4) by simplify blank in the cross section the local coordinate system of inflow muscle die cavity.

In the forming process, the dynamic change of local loading width l is confirmed by formula (5):

l＝l ₀+b ₁s+b ₂s ² (5)

L in the formula ₀Be initial local loading width; S is for loading the patrix stroke; b ₁Be coefficient once; b ₂Be the quadratic term coefficient; b ₁And b ₂Confirm by formula (6) and formula (7) respectively:

ln(b ₁)＝1.16941+0.03880A-0.13668B-0.33010C-0.47077D-0.04376R+0.17274lnA+0.73480lnB-0.39029lnC+0.64892lnR (6)

ln(b ₂)＝-1.01970-0.03751A+0.74384B-0.04876C-0.22359D+1.19454R+0.94165lnA-3.74272lnB-0.45123lnC-1.50094lnR (7)

A is l in the formula ₀The ratio of/b, B are L/l ₀Ratio, C is H ₀The ratio of/b, D are Δ H ₀/ H ₀Ratio; L is the twice of muscle die cavity center to distance between the restrained end of thickness H biscuit area; R is defined as the ratio of width increment Delta l and thickness difference Δ H for becoming the transition condition of caliper zones, is Δ l/ Δ H, and is as shown in Figure 3;

The thickness difference Δ H that becomes caliper zones in the forming process is confirmed by formula (8):

ΔH＝C ₁-s-H (8)

In the formula: C ₁Be Δ H ₀With H ₀Sum; Δ H ₀For original depth poor; H ₀For becoming in the caliper zones not with the initial blank thickness that loads upper mould contact;

Order

K ₁＝L-l ₀，

K ₂＝-b ₁C ₁-b+l ₀，

K ₃＝-2(b ₂C ₁-b ₁)，

${\mathrm{<figure-callout\; id="4"\; label="K"\; filenames="HDA0000138839800000012.png,HDA0000138839800000022.png"\; state="\{\{state\}\}">K</figure-callout>}}_4=b_1-\frac{1}{m}-\frac{{\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HDA0000138839800000013.png,HDA0000138839800000021.png"\; state="\{\{state\}\}">C</figure-callout>}}_1}{2\mathrm{mb}},$

${\mathrm{<figure-callout\; id="5"\; label="K"\; filenames="HDA0000138839800000012.png"\; state="\{\{state\}\}">K</figure-callout>}}_5=2{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="HDA0000138839800000012.png,HDA0000138839800000013.png"\; state="\{\{state\}\}">b</figure-callout>}}_2+\frac{1}{2\mathrm{mb}},$

$K_6=-C_1{\mathrm{<figure-callout\; id="4"\; label="K"\; filenames="HDA0000138839800000012.png,HDA0000138839800000022.png"\; state="\{\{state\}\}">K</figure-callout>}}_4+\frac{1}{2}(l_0-b),$

$K_7=\frac{{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA0000138839800000013.png,HDA0000138839800000021.png"\; state="\{\{state\}\}">b</figure-callout>}}_1}{2}+K_4-C_1{\mathrm{<figure-callout\; id="5"\; label="K"\; filenames="HDA0000138839800000012.png"\; state="\{\{state\}\}">K</figure-callout>}}_5,$

$K_8={\mathrm{<figure-callout\; id="5"\; label="K"\; filenames="HDA0000138839800000012.png"\; state="\{\{state\}\}">K</figure-callout>}}_5+\frac{{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="HDA0000138839800000012.png,HDA0000138839800000013.png"\; state="\{\{state\}\}">b</figure-callout>}}_2}{2},$

Said K ₁～K ₈Be the simplification item in (9) and the formula (10).

Flow into the material volume V of muscle die cavity _InConfirm by formula (9) or formula (10) differential equation group:

Work as σ _x| _X=b/2Have during≤q: $\left\{\begin{array}{c}(K_1-b_{1}s-b_2{s}^2)\frac{\mathrm{DH}}{\mathrm{Ds}}-({\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA0000138839800000013.png,HDA0000138839800000021.png"\; state="\{\{state\}\}">b</figure-callout>}}_1+2b_{2}s)H={\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="HDA0000138839800000012.png,HDA0000138839800000013.png"\; state="\{\{state\}\}">K</figure-callout>}}_2+K_{3}s+3b_2{s}^2\\ \frac{d{V}_{\mathrm{In}}}{\mathrm{Ds}}=\frac{b}{2}\end{array}\right.---\left(9\right)$

Work as σ _x| _X=b/2Have during＞q: $\left\{\begin{array}{c}(K_1-b_{1}s-b_2{s}^2)\frac{\mathrm{DH}}{\mathrm{Ds}}-({\mathrm{<figure-callout\; id="4"\; label="K"\; filenames="HDA0000138839800000012.png,HDA0000138839800000022.png"\; state="\{\{state\}\}">K</figure-callout>}}_4+K_{5}s)H=K_6+K_{7}s+K_8{s}^2\\ \frac{d{V}_{\mathrm{In}}}{\mathrm{Ds}}=\frac{1}{4}(l_0+b+b_{1}s+b_2{s}^2)-\frac{C_1-s-H}{2m}(1+\frac{C_1-s}{2b})\end{array}\right.---\left(10\right)$

Can use numerical method according to initial condition, find the solution formula (9), formula (10), adopt Runge-Kutta method to find the solution formula (9), formula (10) in the present embodiment.

Whole stress state is shown in Fig. 2 d; The blank lower surface cooperates with bed die.Bottom mold surface has the shaping die cavity of rib.Described whole stress state is between each rib shaping die cavity of bed die; Perhaps between the rib shaping die cavity at member one end proximity head place should the end face madial wall of end to said counterdie, perhaps between each rib shaping die cavity of bed die and the rib shaping die cavity at member one end proximity head place should the end face madial wall of end to said counterdie between; And should the zone blank contact fully with loading upper die and lower die, the stress state that this moment should the zone is whole stress state.

When the rib shaping die cavity at member one end proximity head place should be whole stress state between end face madial wall of end to said counterdie, then material shunting layer place arrive this rib shaping die cavity center apart from x _kFor said counterdie is somebody's turn to do the distance of the end face madial wall of end to this rib shaping die cavity center.

When being whole stress state between i muscle die cavity and i+1 the muscle die cavity, then material shunting layer place to i muscle die cavity center apart from x _kConfirm by formula (11):

$x_k=\frac{a_{i,i+1}}{2}+\frac{b_i-b_{i+1}}{4}+\frac{{\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="HDA0000138839800000012.png,HDA0000138839800000013.png"\; state="\{\{state\}\}">H</figure-callout>}}^2}{4m}(\frac{1}{b_{i+1}}-\frac{1}{b_i})---\left(11\right)$

In the formula: a _{I, i+1}It is the distance between i muscle die cavity center and i+1 the muscle die cavity center; b _iThe muscle that is i muscle is wide; b _I+1The muscle that is i+1 muscle is wide; H is for whole stress state zone sotck thinkness occurring; M is the normal shearing friction factor;

Occurring whole stress state zone sotck thinkness H in the forming process is confirmed by formula (12) with the relation that loads patrix stroke s:

H＝H ₀-s (12)

In the formula: H ₀For whole stress state zone initial blank thickness occurring; S is for loading the patrix stroke;

Flow into the material volume V of muscle die cavity _InConfirm by formula (13):

$V_{\mathrm{in}}={\&Integral;}_{s_1}^{s_2}{x}_k\left(s\right)\mathrm{ds}---\left(13\right)$

Step 3 is simplified the high analytical Calculation of cross section local loading and shaping process shaping muscle;

First loads the material volume that flows into each muscle die cavity of simplification cross section in the step calculates:

Confirm that first loads the range of patrix, get and calculate step delta s, Δ s=0.05mm in the present embodiment; In step delta s, according to step 2, confirm to simplify the stress state of the 1st muscle die cavity both sides, cross section, calculate the material volume of the 1st the muscle die cavity that flows into the simplification cross section respectively according to geometric parameter, the friction condition of stress state, muscle die cavity and blank; The 1st muscle die cavity both sides blank do not contact with bed die with mold, and flowing into muscle die cavity material volume is zero; Repeat said process,, confirm the stress state of the 2nd muscle die cavity both sides, the 3rd muscle die cavity both sides, the 4th muscle die cavity both sides, the 5th muscle die cavity both sides and the 6th muscle die cavity both sides respectively according to step 2.Geometric parameter, friction condition according to stress state, muscle die cavity and blank calculate the material volume that flows into the 2nd muscle die cavity, the 3rd muscle die cavity, the 4th muscle die cavity, the 5th muscle die cavity and the 6th muscle die cavity of simplifying the cross section respectively; The 2nd muscle die cavity both sides blank does not contact with bed die with mold, and flowing into muscle die cavity material volume is zero; The 3rd muscle die cavity both sides blank does not contact with bed die with mold, and flowing into muscle die cavity material volume also is zero; The 4th muscle die cavity both sides blank does not contact with bed die with mold, and flowing into muscle die cavity material volume also is zero; The 5th muscle die cavity both sides blank does not contact with bed die with mold, and flowing into muscle die cavity material volume also is zero; The 6th muscle die cavity both sides blank does not contact with bed die with mold, and flowing into muscle die cavity material volume also is zero.So far accomplish the calculating of a step delta s.The material volume of each muscle die cavity that record obtains upgrades the blank geometric parameter and contacts situation.

Based on step 2, repeat said process, continue to confirm the stress state of each muscle die cavity both sides and calculate the material volume that flows into each muscle die cavity.Continue in the process of the stress state of definite each muscle die cavity both sides and the material volume that calculating flows into each muscle die cavity, accumulation calculating step delta s until the range of accomplishing the first loading patrix, obtains flowing into the material volume of each muscle die cavity.

After the calculating in the first loading step of completion, on the blank shape basis of subregion shaping rib, the material volume that carries out each muscle die cavity of inflow simplification cross section in the second loading step calculates:

Confirm that second loads the range of patrix, get and calculate step delta s, Δ s=0.05mm in the present embodiment;

In step delta s, according to step 2, confirm to simplify the stress state of the 1st muscle die cavity both sides, cross section, calculate the material volume of the 1st the muscle die cavity that flows into the simplification cross section respectively according to geometric parameter, the friction condition of stress state, muscle die cavity and blank; The 1st muscle die cavity both sides blank do not contact with bed die with mold, and flowing into muscle die cavity material volume is zero; Repeat said process,, confirm the stress state of the 2nd muscle die cavity both sides, the 3rd muscle die cavity both sides, the 4th muscle die cavity both sides, the 5th muscle die cavity both sides and the 6th muscle die cavity both sides respectively according to step 2.Geometric parameter, friction condition according to stress state, muscle die cavity and blank calculate the material volume that flows into the 2nd muscle die cavity, the 3rd muscle die cavity, the 4th muscle die cavity, the 5th muscle die cavity and the 6th muscle die cavity of simplifying the cross section respectively; The 2nd muscle die cavity both sides blank does not contact with bed die with mold, and flowing into muscle die cavity material volume is zero; The 3rd muscle die cavity both sides blank does not contact with bed die with mold, and flowing into muscle die cavity material volume also is zero; The 4th muscle die cavity both sides blank does not contact with bed die with mold, and flowing into muscle die cavity material volume also is zero; The 5th muscle die cavity both sides blank does not contact with bed die with mold, and flowing into muscle die cavity material volume also is zero; The 6th muscle die cavity both sides blank does not contact with bed die with mold, and flowing into muscle die cavity material volume also is zero.So far accomplish the calculating of a step delta s.The material volume of each muscle die cavity that record obtains upgrades the blank geometric parameter and contacts situation.

Based on step 2, repeat said process, continue to confirm the stress state of each muscle die cavity both sides and calculate the material volume that flows into each muscle die cavity.Continue in the process of the stress state of definite each muscle die cavity both sides and the material volume that calculating flows into each muscle die cavity, accumulation calculating step delta s until the range of accomplishing the second loading patrix, obtains flowing into the material volume of each muscle die cavity.

Accomplish two calculating that load the step, the high h of shaping muscle that simplifies each muscle in the cross section is confirmed by formula (14) respectively:

$h=\frac{V_{\mathrm{in}}^{\mathrm{tot}}}{b}---\left(14\right)$

Flow into the material volume of muscle die cavity in the formula in

whole forming process.

Step 4 is confirmed basically not uniform thickness blank shape;

A. revise not uniform thickness blank based on analysis result, simplify the high analytical Calculation of cross section local loading and shaping process shaping muscle.Revise not uniform thickness blank according to analysis result, and carry out to simplify the high analytical Calculation of cross section local loading and shaping process shaping muscle, when the shaping muscle height that calculates with the difference in height e between the designing requirement muscle height _hMaximum max (e _h) during less than 10-15%, stop to revise blank;

B. the not uniform thickness blank shape that obtains with step a is the basis, and according to the following caliper zones setting principle that becomes, adjustment correction becomes the transition condition R of caliper zones simultaneously:

Become caliper zones transition condition R＞1;

Blank becomes caliper zones and should avoid being arranged near the branch mould position and near the muscle die cavity;

If near muscle die cavity or mould subregion, the change caliper zones is set, need to adopt bigger transition condition, i.e. R＞2;

Obtain the component partial loading and shaping with uniform thickness blank not basically, as shown in Figure 5;

Step 5 is confirmed finally not uniform thickness blank according to the member shape.Confirm not uniform thickness blank through the Computer Numerical Simulation analysis.The forming process of uniform thickness blank not basically in the numerical simulation analysis step 4.Fig. 6 is the whole loading and shaping numerical Simulation of a member model, and this numerical simulator comprises that whole counterdie 6, first loads patrix 7, second and loads patrix 8 and uniform thickness blank 9 not; First loads the step to 7 loadings of the first loading patrix, and the second loading step loaded patrix 8 loadings to second.Two have been satisfied the filling requirement after loading the step, basically not the uniform thickness blank promptly as final blank shape.

Embodiment two:

Present embodiment is that a kind of definite two-dimentional local loading and shaping is used the not method of uniform thickness blank.As shown in Figure 7, the member upper surface of present embodiment and lower surface all are symmetrically distributed with six pairs of ribs; Patrix is divided into two.The material of member is the Ti-6Al-4V titanium alloy.Forming process in the present embodiment has two and loads the step.

In the present embodiment, gusset class A of geometric unitA local loading and shaping adopts ausforming technology, 950 ℃ of forming temperatures, and patrix loading velocity 1mm/s, getting friction factor m is 0.3.

Concrete confirms that uniform thickness blank shape process is not following:

Step 1 is simplified the member shape of cross section;

Member upper surface and lower surface are distributed with rib symmetrically, when simplifying cross section, serve as to simplify the cross section with the surface of symmetrical center line one side of member thickness direction, in the present embodiment, serve as to simplify the cross section with the lower surface of member thickness direction center line.

Simplify the cross section, only lower surface has rib, has six ribs, is that an end of rib begins from the member edge, each rib is remembered successively made the 1st muscle～the 6th muscle.Patrix is divided into two, and the mould district location is between the 4th muscle and the 5th muscle, and the distance at distance the 4th muscle center is 75% of the 4th muscle center and the 5th a muscle centre distance.

Step 2 is confirmed shunting layer position and muscle die cavity filler volume calculation formula according to the stress state of simplifying in the local loading and shaping of cross section.

In definite shunting layer position and during muscle die cavity filler volume calculation formula, each muscle die cavity place of whole counterdie 1 to set up local rectangular coordinate system; The Y coordinate of said local rectangular coordinate system is positioned at the symmetrical centre of muscle die cavity width of living in, and the origin of coordinates of each local rectangular coordinate system is positioned at the intersection point place of this Y coordinate and X coordinate.

The uniform thickness blank is not as initial blank at first to get one, and according to simplifying the required geometry characteristic that does not wait thick stock, mould of section, three kinds of local loading states and a kind of whole stress state appear in meeting in the local loading and shaping process.

First kind of local loading state is shown in Fig. 2 a; The blank lower surface cooperates with bed die.Bottom mold surface has the shaping die cavity of rib.Described first kind of local loading state is positioned at loading zone first muscle die cavity near minute mould position 5, i.e. the 4th muscle die cavity in first local loading step and 5th the muscle die cavity of second local loading in the step are to dividing between the mould position 5; Blank in this zone contacts with loading upper die and lower die fully, and stress state that at this moment should the zone is first kind of local loading state.

Under first kind of local loading state; The local loading width is and occurs in first kind of local loading state region near first muscle die cavity center of minute mould position 5 to dividing two times of distance between the mould position 5; Local loading width l does not change in the stage in local loading, and occurring between the same line journey of sotck thinkness H in first kind of local loading state region is linear relationship.Adopt computing formula (1) calculate first kind of local loading state material shunting layer place down arrive muscle die cavity center apart from x _k:

$\left\{\begin{array}{cc}{x}_k=\frac{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="HDA0000138839800000012.png,HDA0000138839800000013.png"\; state="\{\{state\}\}">b</figure-callout>}}{2}& {\mathrm{\&sigma;}}_x{|}_{x=b/2}\&le;q\\ x_k=\frac{1}{4}(l+b-\frac{{\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="HDA0000138839800000012.png,HDA0000138839800000013.png"\; state="\{\{state\}\}">H</figure-callout>}}^2}{\mathrm{mb}})& {\mathrm{\&sigma;}}_x{|}_{x=b/2}>q\end{array}\right.---\left(1\right)$

Wherein:

${\mathrm{\&sigma;}}_x{|}_{x=b/2}=2K+\frac{\mathrm{mK}}{H}(l-b)$

$q=2K(1+\frac{H}{2b})$

In the formula: K is the material shear yield strength; B is that muscle is wide; L is the local loading width; H is for first kind of local loading state region sotck thinkness occurring; M is the normal shearing friction factor; σ _xDo not flow to the stress of blank X-direction in the web district of muscle die cavity for material, blank contacts with loading upper die and lower die simultaneously in the described web district; Q is the average unit pressure of the X-direction on interior muscle of blank and the web intersection interface, and described muscle and web intersection interface overlap with the muscle cavity lateral.The local coordinate system that is adopted in the formula (1) by simplify blank in the cross section the local coordinate system of inflow muscle die cavity.

Occurring first kind of local loading state region sotck thinkness H in the forming process is confirmed by formula (2) with the relation that loads patrix stroke s:

H＝H ₀-s (2)

In the formula: H ₀, first kind of local loading state region initial blank thickness appears; S loads the patrix stroke;

Flow into the material volume V of muscle die cavity _InConfirm by formula (3):

$V_{\mathrm{in}}={\&Integral;}_{s_1}^{s_2}{x}_k\left(s\right)\mathrm{ds}---\left(3\right)$

Second kind of local loading state is shown in Fig. 2 b; The blank lower surface cooperates with bed die.Bottom mold surface has the shaping die cavity of rib.The 3rd muscle both sides web thickness changes; In second local loading goes on foot; Blank between the 3rd muscle die cavity and the 4th muscle die cavity contacts with loading upper die and lower die fully; And the blank between the 3rd muscle die cavity and the 2nd the muscle die cavity does not contact with loading upper die and lower die fully, and the stress state between this moment the 3rd muscle die cavity and the 4th the muscle die cavity is second kind of local loading state.

Under second kind of local loading state; The local loading width is 3 the muscle die cavities in the 4th muscle die cavity center to the two times near distance between the sidewall of the 4th muscle die cavity; Local loading width l does not change in the stage in local loading, and occurring between the same line journey of sotck thinkness H in second kind of local loading state region is linear relationship.Adopt computing formula (1) calculate second kind of local loading state material shunting layer place down arrive muscle die cavity center apart from x _k:

$\left\{\begin{array}{cc}{x}_k=\frac{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="HDA0000138839800000012.png,HDA0000138839800000013.png"\; state="\{\{state\}\}">b</figure-callout>}}{2}& {\mathrm{\&sigma;}}_x{|}_{x=b/2}\&le;q\\ x_k=\frac{1}{4}(l+b-\frac{{\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="HDA0000138839800000012.png,HDA0000138839800000013.png"\; state="\{\{state\}\}">H</figure-callout>}}^2}{\mathrm{mb}})& {\mathrm{\&sigma;}}_x{|}_{x=b/2}>q\end{array}\right.---\left(1\right)$

Wherein:

${\mathrm{\&sigma;}}_x{|}_{x=b/2}=2K+\frac{\mathrm{mK}}{H}(l-b)$

$q=2K(1+\frac{H}{2b})$

In the formula: K is the material shear yield strength; B is that muscle is wide; L is the local loading width; H is for second kind of local loading state region sotck thinkness occurring; M is the normal shearing friction factor; σ _xDo not flow to the stress of blank X-direction in the web district of muscle die cavity for material, blank contacts with loading upper die and lower die simultaneously in the described web district; Q is the average unit pressure of the X-direction on interior muscle of blank and the web intersection interface, and described muscle and web intersection interface overlap with the muscle cavity lateral.The local coordinate system that is adopted in the formula (1) by simplify blank in the cross section the local coordinate system of inflow muscle die cavity.

Occurring second kind of local loading state region sotck thinkness H in the forming process is confirmed by formula (2) with the relation that loads patrix stroke s:

H＝H ₀-s (2)

In the formula: H ₀For second kind of local loading state region initial blank thickness occurring; S is for loading the patrix stroke;

Flow into the material volume V of muscle die cavity _InConfirm by formula (3):

$V_{\mathrm{in}}={\&Integral;}_{s_1}^{s_2}{x}_k\left(s\right)\mathrm{ds}---\left(3\right)$

The third local loading state is shown in Fig. 2 c; The blank lower surface cooperates with bed die.Bottom mold surface has the shaping die cavity of rib.The surface of said not uniform thickness blank is stepped, and the thickness difference of this ladder is Δ H.Described the third local loading state is between each rib shaping die cavity of bed die; Perhaps between the rib shaping die cavity at member one end proximity head place should the end face madial wall of end to said counterdie, perhaps between each rib shaping die cavity of bed die and the rib shaping die cavity at member one end proximity head place should the end face madial wall of end to said counterdie between; And should contact fully with counterdie by the zone blank, the stress state that this moment should the zone is the third local loading state.

Under the third local loading state; The local loading width is and blank in the third local loading state region occurs with upper die and lower die two times of width of contact portion simultaneously; This local loading width l is dynamic change with loading procedure in local loading in the stage, and occurring between H and the same line journey of Δ H in the third local loading state region is nonlinear correlation.Material shunting layer place under the third local loading state to muscle die cavity center apart from x _kConfirm by formula (4):

$\left\{\begin{array}{cc}{x}_k=\frac{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="HDA0000138839800000012.png,HDA0000138839800000013.png"\; state="\{\{state\}\}">b</figure-callout>}}{2}& {\mathrm{\&sigma;}}_x{|}_{x=b/2}\&le;q\\ x_k=\frac{1}{4}(l+b)-\frac{\mathrm{\&Delta;H}}{2m}(1+\frac{H+\mathrm{\&Delta;H}}{2b})& {\mathrm{\&sigma;}}_x{|}_{x=b/2}>q\end{array}\right.---\left(4\right)$

Wherein:

${\mathrm{\&sigma;}}_x{|}_{x=b/2}=\frac{\mathrm{mK}}{\mathrm{\&Delta;H}}(l-b)$

$q=2K(1+\frac{H+\mathrm{\&Delta;H}}{2b})$

In the formula: K is the material shear yield strength; B is that muscle is wide; L is the local loading width; Δ H is for becoming the thickness difference of caliper zones; H is for becoming in the caliper zones not with the sotck thinkness that loads upper mould contact; M is the normal shearing friction factor; σ _xDo not flow to the stress of blank X-direction in the web district of muscle die cavity for material, blank contacts with loading upper die and lower die simultaneously in the described web district; Q is the average unit pressure of the X-direction on interior muscle of blank and the web intersection interface, and described muscle and web intersection interface overlap with the muscle cavity lateral.The local coordinate system that is adopted in the formula (4) by simplify blank in the cross section the local coordinate system of inflow muscle die cavity.

In the forming process, the dynamic change of local loading width l is confirmed by formula (5):

l＝l ₀+b ₁s+b ₂s ² (5)

L in the formula ₀Be initial local loading width; S is for loading the patrix stroke; b ₁Be coefficient once; b ₂Be the quadratic term coefficient; b ₁And b ₂Confirm by formula (6) and formula (7) respectively:

ln(b ₁)＝1.16941+0.03880A-0.13668B-0.33010C-0.47077D-0.04376R+0.17274lnA+0.73480lnB-0.39029lnC+0.64892lnR (6)

ln(b ₂)＝-1.01970-0.03751A+0.74384B-0.04876C-0.22359D+1.19454R+0.94165lnA-3.74272lnB-0.45123lnC-1.50094lnR (7)

A is l in the formula ₀The ratio of/b, B are L/l ₀Ratio, C is H ₀The ratio of/b, D are Δ H ₀/ H ₀Ratio; L is the twice of muscle die cavity center to distance between the restrained end of thickness H biscuit area; R is defined as the ratio of width increment Delta l and thickness difference Δ H for becoming the transition condition of caliper zones, is Δ l/ Δ H, and is as shown in Figure 3;

The thickness difference Δ H that becomes caliper zones in the forming process is confirmed by formula (8):

ΔH＝C ₁-s-H (8)

In the formula: C ₁Be Δ H ₀With H ₀Sum; Δ H ₀For original depth poor; H ₀For becoming in the caliper zones not with the initial blank thickness that loads upper mould contact;

Order

K ₁＝L-l ₀，

K ₂＝-b ₁C ₁-b+l ₀，

K ₃＝-2(b ₂C ₁-b ₁)，

${\mathrm{<figure-callout\; id="4"\; label="K"\; filenames="HDA0000138839800000012.png,HDA0000138839800000022.png"\; state="\{\{state\}\}">K</figure-callout>}}_4=b_1-\frac{1}{m}-\frac{{\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HDA0000138839800000013.png,HDA0000138839800000021.png"\; state="\{\{state\}\}">C</figure-callout>}}_1}{2\mathrm{mb}},$

${\mathrm{<figure-callout\; id="5"\; label="K"\; filenames="HDA0000138839800000012.png"\; state="\{\{state\}\}">K</figure-callout>}}_5=2{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="HDA0000138839800000012.png,HDA0000138839800000013.png"\; state="\{\{state\}\}">b</figure-callout>}}_2+\frac{1}{2\mathrm{mb}},$

$K_6=-C_1{\mathrm{<figure-callout\; id="4"\; label="K"\; filenames="HDA0000138839800000012.png,HDA0000138839800000022.png"\; state="\{\{state\}\}">K</figure-callout>}}_4+\frac{1}{2}(l_0-b),$

$K_7=\frac{{\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA0000138839800000013.png,HDA0000138839800000021.png"\; state="\{\{state\}\}">b</figure-callout>}}_1}{2}+K_4-C_1{\mathrm{<figure-callout\; id="5"\; label="K"\; filenames="HDA0000138839800000012.png"\; state="\{\{state\}\}">K</figure-callout>}}_5,$

$K_8={\mathrm{<figure-callout\; id="5"\; label="K"\; filenames="HDA0000138839800000012.png"\; state="\{\{state\}\}">K</figure-callout>}}_5+\frac{{\mathrm{<figure-callout\; id="2"\; label="b"\; filenames="HDA0000138839800000012.png,HDA0000138839800000013.png"\; state="\{\{state\}\}">b</figure-callout>}}_2}{2},$

Said K ₁～K ₈Be the simplification item in (9) and the formula (10).

Flow into the material volume V of muscle die cavity _InConfirm by formula (9) or formula (10) differential equation group:

Work as σ _x| _X=b/2Have during≤q: $\left\{\begin{array}{c}(K_1-b_{1}s-b_2{s}^2)\frac{\mathrm{DH}}{\mathrm{Ds}}-({\mathrm{<figure-callout\; id="1"\; label="b"\; filenames="HDA0000138839800000013.png,HDA0000138839800000021.png"\; state="\{\{state\}\}">b</figure-callout>}}_1+2b_{2}s)H={\mathrm{<figure-callout\; id="2"\; label="K"\; filenames="HDA0000138839800000012.png,HDA0000138839800000013.png"\; state="\{\{state\}\}">K</figure-callout>}}_2+K_{3}s+3b_2{s}^2\\ \frac{d{V}_{\mathrm{In}}}{\mathrm{Ds}}=\frac{b}{2}\end{array}\right.---\left(9\right)$

Work as σ _x| _X=b/2Have during＞q: $\left\{\begin{array}{c}(K_1-b_{1}s-b_2{s}^2)\frac{\mathrm{DH}}{\mathrm{Ds}}-({\mathrm{<figure-callout\; id="4"\; label="K"\; filenames="HDA0000138839800000012.png,HDA0000138839800000022.png"\; state="\{\{state\}\}">K</figure-callout>}}_4+K_{5}s)H=K_6+K_{7}s+K_8{s}^2\\ \frac{d{V}_{\mathrm{In}}}{\mathrm{Ds}}=\frac{1}{4}(l_0+b+b_{1}s+b_2{s}^2)-\frac{C_1-s-H}{2m}(1+\frac{C_1-s}{2b})\end{array}\right.---\left(10\right)$

Can use numerical method according to initial condition, find the solution formula (9), formula (10), adopt Runge-Kutta method to find the solution formula (9), formula (10) in the present embodiment.

Whole stress state is shown in Fig. 2 d; The blank lower surface cooperates with bed die.Bottom mold surface has the shaping die cavity of rib.Described whole stress state is between each rib shaping die cavity of bed die; Perhaps between the rib shaping die cavity at member one end proximity head place should the end face madial wall of end to said counterdie, perhaps between each rib shaping die cavity of bed die and the rib shaping die cavity at member one end proximity head place should the end face madial wall of end to said counterdie between; And should the zone blank contact fully with loading upper die and lower die, the stress state that this moment should the zone is whole stress state.

When the rib shaping die cavity at member one end proximity head place should be whole stress state between end face madial wall of end to said counterdie, then material shunting layer place arrive this rib shaping die cavity center apart from x _kFor said counterdie is somebody's turn to do the distance of the end face madial wall of end to this rib shaping die cavity center.

When being whole stress state between i muscle die cavity and i+1 the muscle die cavity, then material shunting layer place to i muscle die cavity center apart from x _kConfirm by formula (11):

$x_k=\frac{a_{i,i+1}}{2}+\frac{b_i-b_{i+1}}{4}+\frac{{\mathrm{<figure-callout\; id="2"\; label="H"\; filenames="HDA0000138839800000012.png,HDA0000138839800000013.png"\; state="\{\{state\}\}">H</figure-callout>}}^2}{4m}(\frac{1}{b_{i+1}}-\frac{1}{b_i})---\left(11\right)$

In the formula: a _{I, i+1}It is the distance between i muscle die cavity center and i+1 the muscle die cavity center; b _iThe muscle that is i muscle is wide; b _I+1The muscle that is i+1 muscle is wide; H is for whole stress state zone sotck thinkness occurring; M is the normal shearing friction factor;

Occurring whole stress state zone sotck thinkness H in the forming process is confirmed by formula (12) with the relation that loads patrix stroke s:

H＝H ₀-s (12)

In the formula: H ₀For whole stress state zone initial blank thickness occurring; S is for loading the patrix stroke;

Flow into the material volume V of muscle die cavity _InConfirm by formula (13):

$V_{\mathrm{in}}={\&Integral;}_{s_1}^{s_2}{x}_k\left(s\right)\mathrm{ds}---\left(13\right)$

Step 3 is simplified the high analytical Calculation of cross section local loading and shaping process shaping muscle;

First loads the material volume that flows into each muscle die cavity of simplification cross section in the step calculates:

Confirm that first loads the range of patrix, get and calculate step delta s, Δ s=0.05mm in the present embodiment;

In step delta s, according to step 2, confirm to simplify the stress state of the 1st muscle die cavity both sides, cross section, calculate the material volume of the 1st the muscle die cavity that flows into the simplification cross section respectively according to geometric parameter, the friction condition of stress state, muscle die cavity and blank; The 1st muscle die cavity both sides blank do not contact with bed die with mold, and flowing into muscle die cavity material volume is zero; Repeat said process,, confirm the stress state of the 2nd muscle die cavity both sides, the 3rd muscle die cavity both sides, the 4th muscle die cavity both sides, the 5th muscle die cavity both sides and the 6th muscle die cavity both sides respectively according to step 2.Geometric parameter, friction condition according to stress state, muscle die cavity and blank calculate the material volume that flows into the 2nd muscle die cavity, the 3rd muscle die cavity, the 4th muscle die cavity, the 5th muscle die cavity and the 6th muscle die cavity of simplifying the cross section respectively; The 2nd muscle die cavity both sides blank does not contact with bed die with mold, and flowing into muscle die cavity material volume is zero; The 3rd muscle die cavity both sides blank does not contact with bed die with mold, and flowing into muscle die cavity material volume also is zero; The 4th muscle die cavity both sides blank does not contact with bed die with mold, and flowing into muscle die cavity material volume also is zero; The 5th muscle die cavity both sides blank does not contact with bed die with mold, and flowing into muscle die cavity material volume also is zero; The 6th muscle die cavity both sides blank does not contact with bed die with mold, and flowing into muscle die cavity material volume also is zero.So far accomplish the calculating of a step delta s.The material volume of each muscle die cavity that record obtains upgrades the blank geometric parameter and contacts situation.

Based on step 2, repeat said process, continue to confirm the stress state of each muscle die cavity both sides and calculate the material volume that flows into each muscle die cavity.In the computational process, accumulation calculating step delta s until the range of accomplishing the first loading patrix, obtains flowing into the material volume of each muscle die cavity.

After the calculating in the first loading step of completion, on the blank shape basis of subregion shaping rib, the material volume that carries out each muscle die cavity of inflow simplification cross section in the second loading step calculates:

Confirm that second loads the range of patrix, get and calculate step delta s, Δ s=0.05mm in the present embodiment;

In step delta s, according to step 2, confirm to simplify the stress state of the 1st muscle die cavity both sides, cross section, calculate the material volume of the 1st the muscle die cavity that flows into the simplification cross section respectively according to geometric parameter, the friction condition of stress state, muscle die cavity and blank; The 1st muscle die cavity both sides blank do not contact with bed die with mold, and flowing into muscle die cavity material volume is zero; Repeat said process,, confirm the stress state of the 2nd muscle die cavity both sides, the 3rd muscle die cavity both sides, the 4th muscle die cavity both sides, the 5th muscle die cavity both sides and the 6th muscle die cavity both sides respectively according to step 2.Geometric parameter, friction condition according to stress state, muscle die cavity and blank calculate the material volume that flows into the 2nd muscle die cavity, the 3rd muscle die cavity, the 4th muscle die cavity, the 5th muscle die cavity and the 6th muscle die cavity of simplifying the cross section respectively; The 2nd muscle die cavity both sides blank does not contact with bed die with mold, and flowing into muscle die cavity material volume is zero; The 3rd muscle die cavity both sides blank does not contact with bed die with mold, and flowing into muscle die cavity material volume also is zero; The 4th muscle die cavity both sides blank does not contact with bed die with mold, and flowing into muscle die cavity material volume also is zero; The 5th muscle die cavity both sides blank does not contact with bed die with mold, and flowing into muscle die cavity material volume also is zero; The 6th muscle die cavity both sides blank does not contact with bed die with mold, and flowing into muscle die cavity material volume also is zero.So far accomplish the calculating of a step delta s.The material volume of each muscle die cavity that record obtains upgrades the blank geometric parameter and contacts situation.

Based on step 2, repeat said process, continue to confirm the stress state of each muscle die cavity both sides and calculate the material volume that flows into each muscle die cavity.In the computational process, accumulation calculating step delta s until the range of accomplishing the second loading patrix, obtains flowing into the material volume of each muscle die cavity.

Accomplish two calculating that load the step, the high h of shaping muscle that simplifies each muscle in the cross section is confirmed by formula (14) respectively:

$h=\frac{V_{\mathrm{in}}^{\mathrm{tot}}}{b}---\left(14\right)$

Flow into the material volume of muscle die cavity in the formula in

whole forming process.

Step 4 is confirmed basically not uniform thickness blank shape;

A. revise not uniform thickness blank based on analysis result, simplify the high analytical Calculation of cross section local loading and shaping process shaping muscle.Revise not uniform thickness blank according to analysis result, and carry out to simplify the high analytical Calculation of cross section local loading and shaping process shaping muscle, when the shaping muscle height that calculates with the difference in height e between the designing requirement muscle height _hMaximum max (e _h) during less than 10-15%, stop to revise blank;

B. the not uniform thickness blank shape that obtains with step a is the basis, and according to the following caliper zones setting principle that becomes, adjustment correction becomes the transition condition R of caliper zones simultaneously:

Become caliper zones transition condition R＞1;

Blank becomes caliper zones and should avoid being arranged near the branch mould position and near the muscle die cavity;

If near muscle die cavity or mould subregion, the change caliper zones is set, need to adopt bigger transition condition, i.e. R＞2.

Obtain the not uniform thickness blank of member thickness direction center line one side.

C. with the not uniform thickness blank mirror image of step b design, make blank upper surface and the lower surface change caliper zones that distributes symmetrically, as shown in Figure 8; Obtain the component partial loading and shaping with uniform thickness blank not basically.

Step 5 is confirmed finally not uniform thickness blank according to the member shape.Confirm not uniform thickness blank through the Computer Numerical Simulation analysis.The forming process of uniform thickness blank not basically in the numerical simulation analysis step 4.Fig. 9 is a component partial loading and shaping numerical Simulation model, and this numerical simulator comprises that whole counterdie 6, first loads patrix 7, second and loads patrix 8 and uniform thickness blank 9 not; First loads the step to 7 loadings of the first loading patrix, and the second loading step loaded patrix 8 loadings to second.Two loading step back the 4th muscle die cavities are not full of fully, based on finite element modelling results modification blank shape, until satisfying the filling requirement, obtain final blank., shown in figure 10 in the present embodiment through once revising the not uniform thickness blank that obtains to satisfy the filling requirement.

Claims (1)

1. a definite two-dimentional local loading and shaping is used the not method of uniform thickness blank, it is characterized in that, may further comprise the steps:

Step 1 is simplified the member shape of cross section; Be distributed with the member of rib for upper surface or lower surface, the member cross section is simplifies the cross section; Being distributed with the cross section of rib symmetrically for upper surface and lower surface, when simplifying cross section, serves as to simplify the cross section with the surface of symmetrical center line one side of member thickness direction; And each rib that will simplify in the cross section is designated as i muscle, i=1～n respectively; The rib of simplifying the cross section that is shaped adopts local loading and shaping, and the mould district location is the center of subregion muscle in the loading; Confirm that the arbitrary position in i muscle～i+1 muscle is a district location, described i=1～n-1;

Step 2 is confirmed shunting layer position and muscle die cavity filler volume calculation formula according to the stress state of simplifying in the local loading and shaping of cross section;

Through carrying out the definite required not uniform thickness of the section blank shape of simplifying of rapid analysis realization to simplifying the cross section; To simplifying the cross section when doing rapid analysis, get one not the uniform thickness blank and confirm to simplify the blank shape in cross section according to initial blank as initial blank; Do in the rapid analysis simplifying the cross section, three kinds of local loading states and a kind of whole stress state are arranged; Said three kinds of local loading states are respectively; Because first kind of local loading state that mould part load to form, the second kind of local loading state that forms by the different depth of different webs district mould, and the third local loading state that causes by the step-thickness difference Δ H of the not step-like surface existence of uniform thickness blank; Each is simplified the cross section carry out rapid analysis, set up local rectangular coordinate system at each muscle die cavity place of whole counterdie; The Y coordinate of said local rectangular coordinate system is positioned at the symmetrical centre of muscle die cavity width of living in, and the origin of coordinates of each local rectangular coordinate system is positioned at the intersection point place of this Y coordinate and X coordinate;

First kind of local loading state; The blank lower surface cooperates with bed die; Bottom mold surface has the shaping die cavity of rib; Described first kind of local loading state first muscle die cavity near minute mould position in loading zone arrives between the branch mould position; Blank in this zone contacts with loading upper die and lower die fully, and stress state that at this moment should the zone is first kind of local loading state;

Under first kind of local loading state; The local loading width is and occurs in first kind of local loading state region near first muscle die cavity center of minute mould position to dividing two times of distance between the mould position; Local loading width l does not change in the stage in local loading, and occurring between the same line journey of sotck thinkness H in first kind of local loading state region is linear relationship; Adopt computing formula (1) calculate first kind of local loading state material shunting layer place down arrive muscle die cavity center apart from x _k:

$\left\{\begin{array}{cc}{x}_k=\frac{b}{2}& {\mathrm{\&sigma;}}_x{|}_{x=b/2}\&le;q\\ x_k=\frac{1}{4}(l+b-\frac{H^2}{\mathrm{mb}})& {\mathrm{\&sigma;}}_x{|}_{x=b/2}>q\end{array}\right.---\left(1\right)$

Wherein:

${\mathrm{\&sigma;}}_x{|}_{x=b/2}=2K+\frac{\mathrm{mK}}{H}(l-b)$

$q=2K(1+\frac{H}{2b})$

In the formula: K is the material shear yield strength; B is that muscle is wide; L is the local loading width; H is for first kind of local loading state region sotck thinkness occurring; M is the normal shearing friction factor; σ _xDo not flow to the stress of blank X-direction in the web district of muscle die cavity for material, blank contacts with loading upper die and lower die simultaneously in the described web district; Q is the average unit pressure of the X-direction on interior muscle of blank and the web intersection interface, and described muscle and web intersection interface overlap with the muscle cavity lateral; The local coordinate system that is adopted in the formula (1) by simplify blank in the cross section the local coordinate system of inflow muscle die cavity;

Occurring first kind of local loading state region sotck thinkness H in the forming process is confirmed by formula (2) with the relation that loads patrix stroke s:

H＝H ₀-s (2)

In the formula: H ₀For first kind of local loading state region initial blank thickness occurring; S is for loading the patrix stroke;

Flow into the material volume V of muscle die cavity _InConfirm by formula (3):

$V_{\mathrm{in}}={\&Integral;}_{s_1}^{s_2}{x}_k\left(s\right)\mathrm{ds}---\left(3\right)$

Second kind of local loading state; The blank lower surface cooperates with bed die; Bottom mold surface has the shaping die cavity of rib; The both sides web thickness of muscle changes; In loading and shaping; Blank between the adjacent muscle die cavity with a side of this muscle die cavity contacts with loading upper die and lower die fully; And the blank between the adjacent muscle die cavity with opposite side of said this muscle die cavity does not contact with loading upper die and lower die fully, and the stress state between the adjacent muscle die cavity with a said side of said this muscle die cavity this moment is second kind of local loading state;

Under second kind of local loading state; The local loading width is said this muscle cavity lateral two times to distance between the adjacent muscle die cavity of this side center; Local loading width l does not change in the stage in local loading, and occurring between the same line journey of sotck thinkness H in second kind of local loading state region is linear relationship; Said muscle cavity lateral is the sidewall that second kind of local loading state one side appears in this muscle die cavity; Adopt formula (1) calculate second kind of local loading state material shunting layer place down arrive muscle die cavity center apart from x _kH in the formula (1) is for second kind of local loading state region sotck thinkness occurring;

Occurring second kind of local loading state region sotck thinkness H in the forming process is confirmed by formula (2) with the relation that loads patrix stroke s: the H in the formula (2) ₀For second kind of local loading state region initial blank thickness occurring;

Flow into the material volume V of muscle die cavity _InConfirm by formula (3);

The third local loading state; The blank lower surface cooperates with bed die; Bottom mold surface has the shaping die cavity of rib; The surface of said not uniform thickness blank is stepped, and the thickness difference of this ladder is Δ H; Described the third local loading state is between each rib shaping die cavity of bed die; Perhaps between the rib shaping die cavity at member one end proximity head place should the end face madial wall of end to said counterdie, perhaps between each rib shaping die cavity of bed die and the rib shaping die cavity at member one end proximity head place should the end face madial wall of end to said counterdie between; And should contact fully with counterdie by the zone blank, the stress state that this moment should the zone is the third local loading state;

Under the third local loading state; The local loading width is and blank in the third local loading state region occurs with upper die and lower die two times of width of contact portion simultaneously; This local loading width l is dynamic change with loading procedure in local loading in the stage, and occurring between H and the same line journey of Δ H in the third local loading state region is nonlinear correlation; Material shunting layer place under the third local loading state to muscle die cavity center apart from x _kConfirm by formula (4):

$\left\{\begin{array}{cc}{x}_k=\frac{b}{2}& {\mathrm{\&sigma;}}_x{|}_{x=b/2}\&le;q\\ x_k=\frac{1}{4}(l+b)-\frac{\mathrm{\&Delta;H}}{2m}(1+\frac{H+\mathrm{\&Delta;H}}{2b})& {\mathrm{\&sigma;}}_x{|}_{x=b/2}>q\end{array}\right.---\left(4\right)$

Wherein:

${\mathrm{\&sigma;}}_x{|}_{x=b/2}=\frac{\mathrm{mK}}{\mathrm{\&Delta;H}}(l-b)$

$q=2K(1+\frac{H+\mathrm{\&Delta;H}}{2b})$

In the formula: K is the material shear yield strength; B is that muscle is wide; L is the local loading width; Δ H is for becoming the thickness difference of caliper zones; H is for becoming in the caliper zones not with the sotck thinkness that loads upper mould contact; M is the normal shearing friction factor; σ _xDo not flow to the stress of blank X-direction in the web district of muscle die cavity for material, blank contacts with loading upper die and lower die simultaneously in the described web district; Q is the average unit pressure of the X-direction on interior muscle of blank and the web intersection interface, and described muscle and web intersection interface overlap with the muscle cavity lateral; The local coordinate system that is adopted in the formula (4) by simplify blank in the cross section the local coordinate system of inflow muscle die cavity;

In the forming process, the dynamic change of local loading width l is confirmed by formula (5):

l＝l ₀+b ₁s+b ₂s ² (5)

L in the formula ₀Be initial local loading width; S is for loading the patrix stroke; b ₁Be coefficient once; b ₂Be the quadratic term coefficient; b ₁And b ₂Confirm by formula (6) and formula (7) respectively:

ln(b ₁)＝1.16941+0.03880A-0.13668B-0.33010C-0.47077D-0.04376R+0.17274lnA+0.73480lnB-0.39029lnC+0.64892lnR (6)

ln(b ₂)＝-1.01970-0.03751A+0.74384B-0.04876C-0.22359D+1.19454R+0.94165lnA-3.74272lnB-0.45123lnC-1.50094lnR (7)

A is l in the formula ₀The ratio of/b, B are L/l ₀Ratio, C is H ₀The ratio of/b, D are Δ H ₀/ H ₀Ratio; L is muscle die cavity center two times to distance between the restrained end of thickness H biscuit area; R is defined as the ratio of width increment Delta l and thickness difference Δ H for becoming the transition condition of caliper zones, is Δ l/ Δ H;

The thickness difference Δ H that becomes caliper zones in the forming process is confirmed by formula (8):

ΔH＝C ₁-s-H (8)

In the formula: C ₁Be Δ H ₀Add H ₀Sum; Δ H ₀For original depth poor; H ₀For becoming in the caliper zones not with the initial blank thickness that loads upper mould contact;

Order

K ₁＝L-l ₀，

K ₂＝-b ₁C ₁-b+l ₀，

K ₃＝-2(b ₂C ₁-b ₁)，

$K_4=b_1-\frac{1}{m}-\frac{C_1}{2\mathrm{mb}},$

$K_5=2b_2+\frac{1}{2\mathrm{mb}},$

$K_6=-C_1{K}_4+\frac{1}{2}(l_0-b),$

$K_7=\frac{b_1}{2}+K_4-C_1{K}_5,$

$K_8=K_5+\frac{b_2}{2},$

Said K ₁～K ₈Be the simplification item in (9) and the formula (10);

Flow into the material volume V of muscle die cavity _InConfirm by formula (9) or formula (10) differential equation group:

Work as σ _x| _X=b/2Have during≤q: $\left\{\begin{array}{c}(K_1-b_{1}s-b_2{s}^2)\frac{\mathrm{DH}}{\mathrm{Ds}}-(b_1+2b_{2}s)H=K_2+K_{3}s+3b_2{s}^2\\ \frac{d{V}_{\mathrm{In}}}{\mathrm{Ds}}=\frac{b}{2}\end{array}\right.---\left(9\right)$

Work as σ _x| _X=b/2Have during＞q: $\left\{\begin{array}{c}(K_1-b_{1}s-b_2{s}^2)\frac{\mathrm{DH}}{\mathrm{Ds}}-(K_4+K_{5}s)H=K_6+K_{7}s+K_8{s}^2\\ \frac{d{V}_{\mathrm{In}}}{\mathrm{Ds}}=\frac{1}{4}(l_0+b+b_{1}s+b_2{s}^2)-\frac{C_1-s-H}{2m}(1+\frac{C_1-s}{2b})\end{array}\right.---\left(10\right)$

Can find the solution formula (9), formula (10) with numerical method according to initial condition;

Whole stress state; The blank lower surface cooperates with bed die; Bottom mold surface has the shaping die cavity of rib; Described whole stress state is between each rib shaping die cavity of bed die; Perhaps between the rib shaping die cavity at member one end proximity head place should the end face madial wall of end to said counterdie, perhaps between each rib shaping die cavity of bed die and the rib shaping die cavity at member one end proximity head place should the end face madial wall of end to said counterdie between; And should the zone blank contact fully with loading upper die and lower die, the stress state that this moment should the zone is whole stress state;

When the rib shaping die cavity at member one end proximity head place should be whole stress state between end face madial wall of end to said counterdie, then material shunting layer place arrive this rib shaping die cavity center apart from x _kFor said counterdie is somebody's turn to do the distance of the end face madial wall of end to this rib shaping die cavity center;

When being whole stress state between i muscle die cavity and i+1 the muscle die cavity, then material shunting layer place to i muscle die cavity center apart from x _kConfirm by formula (11):

$x_k=\frac{a_{i,i+1}}{2}+\frac{b_i-b_{i+1}}{4}+\frac{H^2}{4m}(\frac{1}{b_{i+1}}-\frac{1}{b_i})---\left(11\right)$

In the formula: a _{I, i+1}It is the distance between i muscle die cavity center and i+1 the muscle die cavity center; b _iThe muscle that is i muscle is wide; b _I+1The muscle that is i+1 muscle is wide; H is for whole stress state zone sotck thinkness occurring; M is the normal shearing friction factor;

Occurring whole stress state zone sotck thinkness H in the forming process is confirmed by formula (12) with the relation that loads patrix stroke s:

H＝H ₀-s (12)

In the formula: H ₀For whole stress state zone initial blank thickness occurring; S is for loading the patrix stroke;

Flow into the material volume V of muscle die cavity _InConfirm by formula (13):

$V_{\mathrm{in}}={\&Integral;}_{s_1}^{s_2}{x}_k\left(s\right)\mathrm{ds}---\left(13\right)$

Step 3 is simplified the high analytical Calculation of cross section local loading and shaping process shaping muscle;

First loads the material volume that flows into each muscle die cavity of simplification cross section in the step calculates:

Confirm that first loads the range of patrix, get and calculate step delta s that the span of said Δ s is 0.01～0.1;

In step delta s,, confirm to simplify the stress state of i muscle die cavity both sides, cross section, i=1～n according to step 2; Geometric parameter, friction condition according to stress state, muscle die cavity and blank calculate the material volume that flows into i muscle die cavity simplifying the cross section respectively; I muscle die cavity both sides blank do not contact with bed die with mold, and flowing into muscle die cavity material volume is zero; So far accomplish the calculating of a step delta s; The material volume of each muscle die cavity that record obtains upgrades the blank geometric parameter and contacts situation;

According to step 2, repeat said process, continue to confirm the stress state of each muscle die cavity both sides and calculate the material volume that flows into each muscle die cavity; Said continuation is confirmed the stress state of each muscle die cavity both sides and is calculated in the material volume process that flows into each muscle die cavity, and accumulation calculating step delta s until the range of accomplishing the first loading patrix, obtains flowing into the material volume of each muscle die cavity;

After the calculating in the first loading step of completion, on the blank shape basis of subregion shaping rib, the material volume that carries out each muscle die cavity of inflow simplification cross section in the second loading step calculates:

Confirm that second loads the range of patrix, get and calculate step delta s that the span of said Δ s is 0.01～0.1;

In step delta s,, confirm to simplify the stress state of i muscle die cavity both sides, cross section, i=1～n according to step 2; Geometric parameter, friction condition according to stress state, muscle die cavity and blank calculate the material volume that flows into i muscle die cavity simplifying the cross section respectively; I muscle die cavity both sides blank do not contact with bed die with mold, and flowing into muscle die cavity material volume is zero; So far accomplish the calculating of a step delta s; The material volume of each muscle die cavity that record obtains upgrades the blank geometric parameter and contacts situation;

According to step 2, repeat said process, continue to confirm the stress state of each muscle die cavity both sides and calculate the material volume that flows into each muscle die cavity; The stress state and the calculating that continue definite each muscle die cavity both sides flow in the material volume process of each muscle die cavity, and accumulation calculating step delta s until the range of accomplishing the second loading patrix, obtains flowing into the material volume of each muscle die cavity;

Accomplish two calculating that load the step, the high h of shaping muscle that simplifies each muscle in the cross section is confirmed by formula (14) respectively:

$h=\frac{V_{\mathrm{in}}^{\mathrm{tot}}}{b}---\left(14\right)$

Flow into the material volume of muscle die cavity in the formula in

whole forming process;

Step 4 is confirmed basically not uniform thickness blank shape;

I is distributed with the member of rib for upper surface or lower surface:

A. revise not uniform thickness blank based on analysis result, simplify the high analytical Calculation of cross section local loading and shaping process shaping muscle; Revise not uniform thickness blank according to analysis result, and carry out to simplify the high analytical Calculation of cross section local loading and shaping process shaping muscle, when the shaping muscle height that calculates with the difference in height e between the designing requirement muscle height _hMaximum max (e _h) during less than 10-15%, stop to revise blank; Obtain not uniform thickness blank shape

B. be the basis with the not uniform thickness blank shape that obtains, simultaneously based on following principle, adjustment correction becomes the transition condition R of caliper zones:

Become caliper zones transition condition R＞1;

Blank becomes caliper zones and should avoid being arranged near the branch mould position and near the muscle die cavity;

If near muscle die cavity or mould subregion, the change caliper zones is set, need to adopt bigger transition condition, i.e. R＞2;

Obtain the component partial loading and shaping with uniform thickness blank not basically;

II is distributed with the cross section of rib symmetrically for upper surface and lower surface,

A. revise not uniform thickness blank based on analysis result, simplify the high analytical Calculation of cross section local loading and shaping process shaping muscle; Revise not uniform thickness blank according to analysis result, and carry out to simplify the high analytical Calculation of cross section local loading and shaping process shaping muscle, when the shaping muscle height that calculates with the difference in height e between the designing requirement muscle height _hMaximum max (e _h) during less than 10-15%, stop to revise blank; Obtain not uniform thickness blank shape;

B. be the basis with the not uniform thickness blank shape that obtains, revise the transition condition R that becomes caliper zones based on following principle adjustment simultaneously:

Become caliper zones transition condition R＞1;

Blank becomes caliper zones and should avoid being arranged near the branch mould position and near the muscle die cavity;

If near muscle die cavity or mould subregion, the change caliper zones is set, need to adopt bigger transition condition, i.e. R＞2;

Obtain the not uniform thickness blank of member thickness direction center line one side;

The not uniform thickness blank mirror image that c. will obtain makes blank upper surface and the lower surface change caliper zones that distributes symmetrically; Obtain the component partial loading and shaping with uniform thickness blank not basically;

Step 5 is confirmed finally not uniform thickness blank according to the member shape; Confirm not uniform thickness blank through the Computer Numerical Simulation analysis; The forming process of uniform thickness blank not basically in the numerical simulation analysis step 4; First loads the step to the first loading patrix loading, and the second loading step loaded the patrix loading to second; Two load the step back if member shape unmet filling requirement is then revised blank shape according to numerical simulation result, until the not uniform thickness blank that is met the filling requirement.

Images