CN108694269A - The equal bearing methods of cruciform joint toe of weld and weld seam are realized using structural stress method - Google Patents
The equal bearing methods of cruciform joint toe of weld and weld seam are realized using structural stress method Download PDFInfo
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Abstract
The equal bearing methods of cruciform joint toe of weld and weld seam are realized using structural stress method, it is related to the connector design field under fatigue load, is specifically related to carry the design of cruciform joint Size of welds.It is an object of the invention to design the problem for not considering that the influence and acquired connector weight of weld defect are excessive, heat input is excessive for existing carrying cruciform joint.The equal bearing methods of cruciform joint toe of weld and weld seam are realized using structural stress method:Establish or change cruciform joint model, extract the lateral nodal force of toe of weld and root of weld specified cross-section and longitudinal nodal force, it calculates toe of weld and root of weld equivalent structure stress and is compared, calculate connector mathematic(al) expectation value, and compared with projected life, until connector mathematic(al) expectation value and projected life * safety coefficient ratio Man Zu [1,1.1], that is, complete the equal carryings design of cruciform joint toe of weld and weld seam.Present invention is mainly used for realize that the equal of cruciform joint toe of weld and weld seam carry.
Description
Technical field
The present invention relates to the connector design fields under fatigue load, are specifically related to setting for carrying cruciform joint Size of welds
Meter.
Background technology
For cruciform joint fatigue failure, common there are two types of failure modes:Root of weld fails and toe of weld failure, and toe of weld is lost
Effect, crackle is equivalent to be extended in base material, is easy monitoring and crack growth rate is slow;And when crackle is when root of weld position generates,
Crack propagation path is weld metal zone, monitors that remaining life is less than 20% when macroscopic cracking, is major safety risks, it is therefore necessary to
Rationally designing welding point avoids root of weld from failing.Only there is defined to weld size minimum value in traditional cruciform joint design,
And it is not intended that the light-weight design of joint structure, and the Forming Quality of cruciform joint had not been considered.Connector light-weight design
It is of great significance for mitigating connector weight, reduction weld defect etc..For actual welding connector, due to the concentration heat of welding
High-temperature gradient distribution and inappropriate welding loading etc. caused by effect often will produce axis deviation, and angular deformation is even not
The defects of fusion, in this case under critical Size of welds be varied from certainly.Therefore, there is an urgent need for develop set of system
Method solves the above problems.
Invention content
It is an object of the invention to not consider the influence of weld defect, Yi Jisuo for existing carrying cruciform joint design
The problem that connector weight is excessive, heat input is excessive is obtained, and provides and realizes cruciform joint toe of weld and weld seam using structural stress method
Equal bearing methods.
The equal bearing methods that cruciform joint toe of weld and weld seam are realized using structural stress method, are specifically realized by the following steps
's:
One, establish or change cruciform joint model:Under the conditions of stress ratio R=0, cruciform joint two dimensional model is established, it is non-to hold
Support plate thickness T and carrying plate thickness t is according to the determination of Practical Project demand, S1For along the Size of welds of loading plate, S2For along non-bearing
The Size of welds of plate, and S1Initial value it is equal with t, S2Initial value it is equal with t, p is fusion penetration;Stress ratio R is
Wherein σminFor minimum external applied load, σmaxFor maximum external applied load;
Two, 1., the lateral nodal force f of extraction toe of weld position specified cross-sectionxiWith longitudinal node of toe of weld position specified cross-section
Power fyi, toe of weld position specified cross-section is toe of weld position along loading plate plate thickness direction section;2., extraction root of weld position is specified cuts
The lateral nodal force F in facexiWith longitudinal nodal force F of root of weld position specified cross-sectionyi, root of weld position specified cross-section is root of weld
The section of position and loading plate direction in 90 °;
Three, 1., according to formula (1) toe of weld section membrane stress σ is calculatedm,
σ in formula (1)mFor toe of weld section membrane stress, l is toe crack extensions path length, and
2., toe of weld section flexure stress σ calculated according to formula (2)b,
σ in formula (2)bFor toe of weld section flexure stress, yiBetween toe of weld position section interior joint i and node 1 away from
From node 1 is toe of weld position stress concentration point;
3., toe of weld cross-sectional shear power τ calculated according to formula (3)T,
τ in formula (3)TFor toe of weld cross-sectional shear power;
Four, the equivalent structure stress Δ S at toe of weld position is calculated according to formula (4)S A,
Δ S in formula (4)s AFor the equivalent structure stress at toe of weld position, m is material constant, the m=of aluminium alloy cruciform joint
3.6, the m=3.13 of steel cruciform joint,For load flex than dimensionless function;
Aluminium alloy cruciform joint is calculated according to formula (5)Steel cruciform joint is calculated according to formula (6)
R is toe of weld bend ratio in formula (5) and formula (6), and r is calculated according to formula (7),
When there are axis deviations with angular deformation for test specimen, it is modified using formula (8), obtains revised toe of weld position
Equivalent structure stress Δ σf A;
Δ σ in formula (8)f AFor the equivalent structure stress of revised toe of weld position, P is plus load;
K is calculated according to formula (9)e,
L is test length in formula (9), i.e., test specimen total length subtracts clamping length, and Lc is additional bending moment action length, Lc
=L/2-T/2, e are the axis deviation value of cruciform joint,
K is calculated according to formula (10)α,
α is cruciform joint angular deformation radian value in formula (10);
Five, root of weld position 1., according to formula (11) is calculated along the membrane stress σ for assuming cracking angles theta sectionm(θ),
σ in formula (11)m(θ) is membrane stress of the root of weld position along hypothesis cracking angles theta section, and θ is the hypothesis of root of weld position
Cracking angle indicates to assume that the angle that cracking face is formed by with loading plate, l (θ) are that crackle extends road along cracking angles theta root crack
Electrical path length;
L (θ) is calculated using formula (12),
2., root of weld position calculated along the bending stress σ for assuming cracking angles theta section according to formula (13)b(θ),
σ in formula (13)b(θ) is root of weld position along the bending stress for assuming cracking angles theta section, YiFor root of weld position section
The distance between interior joint i and node 1, node 1 are root of weld position stress concentration points;
3., root of weld position calculated along the shearing force τ for assuming cracking angles theta section according to formula (14)T(θ),
τ in formula (14)T(θ) is root of weld position along the shearing force for assuming cracking angles theta section;
Six, root of weld position is calculated along the equivalent structure stress Δ S for assuming cracking angles theta section according to formula (15)S(θ)B,
Δ S in formula (15)S(θ)BThe equivalent structure stress in cracking angles theta section is assumed for root of weld position edge,
For load flex than dimensionless function;
Aluminium alloy cruciform joint is calculated according to formula (16)Steel cruciform joint is calculated according to formula (17)
R (θ) is root of weld bend ratio in formula (16) and formula (17);
R (θ) is calculated according to formula (18),
Seven, derivation is carried out to θ using formula (15) using method of derivation, finds out θ and existsBetween Δ Ss(θ)BMaximum
Value, is denoted as Δ Ss B, Δ Ss BThe as equivalent structure stress at root of weld position, Δ Ss BCorresponding angle, θ is when root of weld failure occurs
Cracking angle predicted value;
Eight, by the equivalent structure stress Δ S at toe of weld positionS AWith root of weld position equivalent structure stress Δ Ss BIt is compared, when
Test specimen then utilizes the equivalent structure stress Δ σ of revised toe of weld position there are when axis deviation and angular deformationf AInstead of toe of weld position
Equivalent structure stress Δ SS AWith root of weld position equivalent structure stress Δ Ss BIt is compared, and is carried outInspection, ifThen increase the Size of welds S along non-bearing plate2, it is denoted as S2', then utilize S2' replace S2Again it models;
Nine, step 2 is repeated to eight, until
Ten, the result of calculation obtained using step 9 is carried outInspection, if being unsatisfactory forThen subtract
The small Size of welds S along non-bearing plate2, it is denoted as S2", then utilize S2" replace S2Rebuild mould;
11, step 2 is repeated to ten, until
12, it carries out connector mathematic(al) expectation value N to the result of calculation obtained using step 11 to calculate, and connector is calculated
Life value N and projected life N (design) is compared;
The connector mathematic(al) expectation value N of aluminium alloy cruciform joint is calculated according to formula (19), the connector meter of steel cruciform joint
Life value N is calculated to calculate according to formula (20);
N is connector mathematic(al) expectation value, Δ S in formula (19) and formula (20)S AFor toe of weld position equivalent structure stress, work as examination
Part utilizes the equivalent structure stress Δ σ of revised toe of weld position there are when axis deviation and angular deformationf AInstead of toe of weld position etc.
Imitate structural stress Δ SS A;
If 13, being unsatisfactory forF is safety coefficient in formula, is keeping S1/S2The constant basis of ratio
Size of welds S of the upper while increase along loading plate1With the Size of welds S along non-bearing plate2, it is denoted as S1 *And S2 *, utilize S1 *Instead of
S1, utilize S2 *Instead of S2Rebuild mould;
14, step 2 is repeated to 13, until
If 15, being unsatisfactory forWhen, keeping S1/S2Reduce edge simultaneously on the basis of ratio is constant
The Size of welds S of loading plate1With the Size of welds S along non-bearing plate2, it is denoted as S1 **And S2 **, utilize S1 **Instead of S1, utilize S2 **
Instead of S2Rebuild mould;
16, step 2 is repeated to 13, untilThat is N meets
Complete the equal carryings design of cruciform joint toe of weld and weld seam.
The present invention realizes that the principle of the equal bearing methods of cruciform joint toe of weld and weld seam is using structural stress method:Using containing
The given finite element model for not merging defect calculates nodal force, using structural stress method to axis deviation and the production of angular deformation defect
Raw influence obtains the equivalent structure stress of toe of weld and root of weld position after being modified, and constantly changes Size of welds until two positions
Equivalent structure stress ratio and mathematic(al) expectation be satisfied by requirement.Weld defect had both been considered in this way for fatigue failure mode
Influence, got back and met the critical Size of welds of light-weight design.
Advantage of the present invention:One, the present invention consider do not merge, axis deviation and this kind of weld defect of angular deformation are to fatigue failure
The influence of pattern;Two, the Size of welds that the present invention obtains has accomplished light-weight design while ensureing weld seam bearing capacity;
Three, the present invention devises the Size of welds along loading plate and the Size of welds along non-bearing plate simultaneously.
Description of the drawings
Fig. 1 is the present invention realized using structural stress method cruciform joint toe of weld and weld seam equal bearing methods flow signal
Figure;
Fig. 2 is that cruciform joint 1/4 models schematic diagram, S in figure1Indicate the Size of welds along loading plate, S2It indicates along non-bearing
The Size of welds of plate, T indicate that non-bearing plate thickness, t indicate carrying plate thickness;The modeling signal of cruciform joint 1/4
Fig. 3 is nodal force extraction schematic diagram, f in figurexi(fx1~fx6) show the lateral nodal force of toe of weld position specified cross-section,
fyi(fy1~fy6) indicate longitudinal nodal force of toe of weld position specified cross-section, Fxi(Fx1~Fx10) indicate root of weld position specified cross-section
Lateral nodal force, Fyi(Fy1~Fy10) indicate longitudinal nodal force of root of weld position specified cross-section;
Fig. 4 is 1/4 cruciform joint schematic diagram, and θ indicates that the hypothesis cracking angle of root of weld position, p indicate fusion penetration, S in figure1It indicates
Along the Size of welds of loading plate, S2Indicate the Size of welds along non-bearing plate.
Specific implementation mode
Specific implementation mode one:Present embodiment be using structural stress method realize cruciform joint toe of weld and weld seam etc. hold
Support method is specifically realized by the following steps:
One, establish or change cruciform joint model:Under the conditions of stress ratio R=0, cruciform joint two dimensional model is established, it is non-to hold
Support plate thickness T and carrying plate thickness t is according to the determination of Practical Project demand, S1For along the Size of welds of loading plate, S2For along non-bearing
The Size of welds of plate, and S1Initial value it is equal with t, S2Initial value it is equal with t, p is fusion penetration;Stress ratio R is
Wherein σminFor minimum external applied load, σmaxFor maximum external applied load;
Two, 1., the lateral nodal force f of extraction toe of weld position specified cross-sectionxiWith longitudinal node of toe of weld position specified cross-section
Power fyi, toe of weld position specified cross-section is toe of weld position along loading plate plate thickness direction section;2., extraction root of weld position is specified cuts
The lateral nodal force F in facexiWith longitudinal nodal force F of root of weld position specified cross-sectionyi, root of weld position specified cross-section is root of weld
The section of position and loading plate direction in 90 °;
Three, 1., according to formula (1) toe of weld section membrane stress σ is calculatedm,
σ in formula (1)mFor toe of weld section membrane stress, l is toe crack extensions path length, and
2., toe of weld section flexure stress σ calculated according to formula (2)b,
σ in formula (2)bFor toe of weld section flexure stress, yiBetween toe of weld position section interior joint i and node 1 away from
From node 1 is toe of weld position stress concentration point;
3., toe of weld cross-sectional shear power τ calculated according to formula (3)T,
τ in formula (3)TFor toe of weld cross-sectional shear power;
Four, the equivalent structure stress Δ S at toe of weld position is calculated according to formula (4)S A,
Δ S in formula (4)s AFor the equivalent structure stress at toe of weld position, m is material constant, the m=of aluminium alloy cruciform joint
3.6, the m=3.13 of steel cruciform joint,For load flex than dimensionless function;
Aluminium alloy cruciform joint is calculated according to formula (5)Steel cruciform joint is calculated according to formula (6)
R is toe of weld bend ratio in formula (5) and formula (6), and r is calculated according to formula (7),
When there are axis deviations with angular deformation for test specimen, it is modified using formula (8), obtains revised toe of weld position
Equivalent structure stress Δ σf A;
Δ σ in formula (8)f AFor the equivalent structure stress of revised toe of weld position, P is plus load;
K is calculated according to formula (9)e,
L is test length in formula (9), i.e., test specimen total length subtracts clamping length, and Lc is additional bending moment action length, Lc
=L/2-T/2, e are the axis deviation value of cruciform joint,
K is calculated according to formula (10)α,
α is cruciform joint angular deformation radian value in formula (10);
Five, root of weld position 1., according to formula (11) is calculated along the membrane stress σ for assuming cracking angles theta sectionm(θ),
σ in formula (11)m(θ) is membrane stress of the root of weld position along hypothesis cracking angles theta section, and θ is the hypothesis of root of weld position
Cracking angle indicates to assume that the angle that cracking face is formed by with loading plate, l (θ) are that crackle extends road along cracking angles theta root crack
Electrical path length;
L (θ) is calculated using formula (12),
2., root of weld position calculated along the bending stress σ for assuming cracking angles theta section according to formula (13)b(θ),
σ in formula (13)b(θ) is root of weld position along the bending stress for assuming cracking angles theta section, YiFor root of weld position section
The distance between interior joint i and node 1, node 1 are root of weld position stress concentration points;
3., root of weld position calculated along the shearing force τ for assuming cracking angles theta section according to formula (14)T(θ),
τ in formula (14)T(θ) is root of weld position along the shearing force for assuming cracking angles theta section;
Six, root of weld position is calculated along the equivalent structure stress Δ S for assuming cracking angles theta section according to formula (15)S(θ)B,
Δ S in formula (15)S(θ)BThe equivalent structure stress in cracking angles theta section is assumed for root of weld position edge,
For load flex than dimensionless function;
Aluminium alloy cruciform joint is calculated according to formula (16)Steel cruciform joint is calculated according to formula (17)
R (θ) is root of weld bend ratio in formula (16) and formula (17);
R (θ) is calculated according to formula (18),
Seven, derivation is carried out to θ using formula (15) using method of derivation, finds out θ and existsBetween Δ Ss(θ)BMaximum
Value, is denoted as Δ Ss B, Δ Ss BThe as equivalent structure stress at root of weld position, Δ Ss BCorresponding angle, θ is when root of weld failure occurs
Cracking angle predicted value;
Eight, by the equivalent structure stress Δ S at toe of weld positionS AWith root of weld position equivalent structure stress Δ Ss BIt is compared, when
Test specimen then utilizes the equivalent structure stress Δ σ of revised toe of weld position there are when axis deviation and angular deformationf AInstead of toe of weld position
Equivalent structure stress Δ SS AWith root of weld position equivalent structure stress Δ Ss BIt is compared, and is carried outInspection, ifThen increase the Size of welds S along non-bearing plate2, it is denoted as S2', then utilize S2' replace S2Again it models;
Nine, step 2 is repeated to eight, until
Ten, the result of calculation obtained using step 9 is carried outInspection, if being unsatisfactory forThen subtract
The small Size of welds S along non-bearing plate2, it is denoted as S2", then utilize S2" replace S2Rebuild mould;
11, step 2 is repeated to ten, until
12, it carries out connector mathematic(al) expectation value N to the result of calculation obtained using step 11 to calculate, and connector is calculated
Life value N and projected life N (design) is compared;
The connector mathematic(al) expectation value N of aluminium alloy cruciform joint is calculated according to formula (19), the connector meter of steel cruciform joint
Life value N is calculated to calculate according to formula (20);
N is connector mathematic(al) expectation value, Δ S in formula (19) and formula (20)S AFor toe of weld position equivalent structure stress, work as examination
Part utilizes the equivalent structure stress Δ σ of revised toe of weld position there are when axis deviation and angular deformationf AInstead of toe of weld position etc.
Imitate structural stress Δ SS A;
If 13, being unsatisfactory forF is safety coefficient in formula, is keeping S1/S2The constant basis of ratio
Size of welds S of the upper while increase along loading plate1With the Size of welds S along non-bearing plate2, it is denoted as S1 *And S2 *, utilize S1 *Instead of
S1, utilize S2 *Instead of S2Rebuild mould;
14, step 2 is repeated to 13, until
If 15, being unsatisfactory forWhen, keeping S1/S2Reduce edge simultaneously on the basis of ratio is constant
The Size of welds S of loading plate1With the Size of welds S along non-bearing plate2, it is denoted as S1 **And S2 **, utilize S1 **Instead of S1, utilize S2 **
Instead of S2Rebuild mould;
16, step 2 is repeated to 13, untilThat is N meets
Complete the equal carryings design of cruciform joint toe of weld and weld seam.
Due to the grid insensitivity of structural stress method, so present embodiment does not have particular/special requirement for size of mesh opening,
Grid property is set as plane strain unit.Added material attribute and boundary condition carry out finite element analysis computation.Since this has
Finite element analysis process is statics Analysis, therefore material properties need to only use Young's modulus and Poisson's ratio, according to practical base material power
Learn performance design.Present embodiment is designed mainly for the connector in middle high cycle fatigue (more than 10000 cycle cycles), because
This loading environment is designed as the load amplitude under actual cycle load.
Should be noted that when extracting nodal force in present embodiment step 2, which will extract part, separates, for root of weld position
It should be noted that retaining unit below, because the unit of lower section shares root of weld node and can generate power to the node
Relationship.
Specific implementation mode two:The difference of present embodiment and specific implementation mode one is:As stress ratio R in step 1
More than 0, formula (4) is replaced with into formula (21);Formula (15) is replaced with into formula (22),
Other are same as the specific embodiment one.
Specific implementation mode three:One of present embodiment and specific implementation mode one or two difference are:In step 1 when
Stress ratio R is less than 0, and formula (4) is replaced with formula (23);Formula (15) is replaced with into formula (24),
Other are the same as one or two specific embodiments.
Specific implementation mode four:One of present embodiment and specific implementation mode one to three difference are:It is sharp in step 7
Method of derivation is replaced with the method for exhaustion, with step-lengthExhaustive sectionInterior Δ SS(θ)B, find Δ Ss(θ)BMaximum value, note
For Δ Ss B.Other are identical as specific implementation mode one to three.
The content of present invention is not limited only to the content of the respective embodiments described above, the group of one of them or several specific implementation modes
Contract sample can also realize the purpose of invention.
Using following verification experimental verifications effect of the present invention
Embodiment 1:The equal bearing methods that cruciform joint toe of weld and weld seam are realized using structural stress method, specifically by following
What step was completed:The material of the cruciform joint is aluminium alloy;
One, establish or change cruciform joint model:Under the conditions of stress ratio R=0, cruciform joint two dimensional model is established, it is non-to hold
Support plate thickness T=10mm, carrying plate thickness t=10mm, S1For along the Size of welds of loading plate, S2For along the leg of non-bearing plate
Size, and S1Initial value it is equal with t, i.e. S1=10mm, S2Initial value it is equal with t, i.e. S2=10mm, p are fusion penetration, p=
0mm;Stress ratio R isWherein σminFor minimum external applied load σmin=0, σmaxFor maximum external applied load σmax=90MPa;
Two, 1., the lateral nodal force f of extraction toe of weld position specified cross-sectionxiWith longitudinal node of toe of weld position specified cross-section
Power fyi, toe of weld position specified cross-section is toe of weld position along loading plate plate thickness direction section;2., extraction root of weld position is specified cuts
The lateral nodal force F in facexiWith longitudinal nodal force F of root of weld position specified cross-sectionyi, root of weld position specified cross-section is root of weld
The section of position and loading plate direction in 90 °;The results are shown in Table 1 for extraction;
Table 1
Three, 1., according to formula (1) toe of weld section membrane stress σ is calculatedm,
σ in formula (1)mFor toe of weld section membrane stress, l is toe crack extensions path length, andσm=90MPa;
2., toe of weld section flexure stress σ calculated according to formula (2)b,
σ in formula (2)bFor toe of weld section flexure stress, yiBetween toe of weld position section interior joint i and node 1 away from
From node 1 is toe of weld position stress concentration point, σb=47.4773MPa;
3., toe of weld cross-sectional shear power τ calculated according to formula (3)T,
τ in formula (3)TFor toe of weld cross-sectional shear power, τT=-18.5126;
Four, the equivalent structure stress Δ S at toe of weld position is calculated according to formula (4)S A,
Δ S in formula (4)s AFor the equivalent structure stress at toe of weld position, m is material constant, the m=of aluminium alloy cruciform joint
3.6For load flex than dimensionless function;
Aluminium alloy cruciform joint is calculated according to formula (5)
R is toe of weld bend ratio in formula (5), and r is calculated according to formula (7),
R=0.6547 in the present embodiment;
There are axis deviations and angular deformation for aluminium alloy cruciform joint, therefore are modified using formula (8), obtain revised
The equivalent structure stress Δ σ of toe of weld positionf A, Δ σ in the present embodimentf A=166.1487;
Δ σ in formula (8)f AFor the equivalent structure stress of revised toe of weld position, P is plus load, P=90MPa;
K is calculated according to formula (9)e,
L is test length in formula (9), i.e., test specimen total length subtracts clamping length, and Lc is additional bending moment action length,
Lc=L/2-T/2, e are the axis deviation value of cruciform joint, wherein L=160mm, Lc=75mm, e=0.07mm, Ke
=0.01864;
K is calculated according to formula (10)α,
α is cruciform joint angular deformation radian value in formula (10), α=0.005236rad, K in embodimentα=
0.041497;
Five, root of weld position 1., according to formula (11) is calculated along the membrane stress σ for assuming cracking angles theta sectionm(θ),
σ in formula (11)m(θ) is membrane stress of the root of weld position along hypothesis cracking angles theta section, and θ is the hypothesis of root of weld position
Cracking angle indicates to assume that the angle that cracking face is formed by with loading plate, l (θ) are that crackle extends road along cracking angles theta root crack
Electrical path length;
L (θ) is calculated using formula (12),
2., root of weld position calculated along the bending stress σ for assuming cracking angles theta section according to formula (13)b(θ),
σ in formula (13)b(θ) is root of weld position along the bending stress for assuming cracking angles theta section, YiFor root of weld position section
The distance between interior joint i and node 1, node 1 are root of weld position stress concentration points;
3., root of weld position calculated along the shearing force τ for assuming cracking angles theta section according to formula (14)T(θ),
τ in formula (14)T(θ) is root of weld position along the shearing force for assuming cracking angles theta section;
Six, root of weld position is calculated along the equivalent structure stress Δ S for assuming cracking angles theta section according to formula (15)S(θ)B,
Δ S in formula (15)S(θ)BThe equivalent structure stress in cracking angles theta section is assumed for root of weld position edge,
For load flex than dimensionless function;
Aluminium alloy cruciform joint is calculated according to formula (16)
R (θ) is root of weld bend ratio in formula (16);
R (θ) is calculated according to formula (18),
Seven, derivation is carried out to θ using formula (15) using method of derivation, finds out θ and existsBetween Δ Ss(θ)BMaximum
Value, is denoted as Δ Ss B, Δ Ss BThe as equivalent structure stress at root of weld position, Δ Ss BCorresponding angle, θ is when root of weld failure occurs
Cracking angle predicted value, pass through calculate Δ Ss B=173.3986, corresponding θ=72 °;
Eight, by the equivalent structure stress Δ S at toe of weld positionS AWith root of weld position equivalent structure stress Δ Ss BIt is compared, when
Test specimen then utilizes the equivalent structure stress Δ σ of revised toe of weld position there are when axis deviation and angular deformationf AInstead of toe of weld position
Equivalent structure stress Δ SS AWith root of weld position equivalent structure stress Δ Ss BIt is compared, is foundThen increase along non-
The Size of welds S of loading plate2, it is denoted as S2', enable S2Then '=11 utilize S2' replace S2Again it models;
Nine, step 2 is repeated to eight, obtains Δ σ at this timef A=167.6795, Δ Ss B=169.4679, still it is unsatisfactory forRequirement, therefore continue growing S2, enable S2'=12 model again, and repeat step 2 to step 8, obtain at this time
Δσf A=168.9037, Δ Ss B=166.2352, it meets at this timeRequirement, therefore jump out cycle;
Ten, the result of calculation obtained using step 9 is carried outInspection, at this time
Therefore it is not required to be recycled, be directly entered in next step;
11, because meetingRequirement without being recycled, be directly entered in next step;
12, it carries out connector mathematic(al) expectation value N to the result of calculation obtained using step 11 to calculate, and connector is calculated
Life value N and projected life N (design) is compared;
The connector mathematic(al) expectation value N of aluminium alloy cruciform joint is calculated according to formula (19);
N is connector mathematic(al) expectation value, Δ S in formula (19)S AFor toe of weld position equivalent structure stress, when that there are axis is inclined for test specimen
When difference is with angular deformation, the equivalent structure stress Δ σ of revised toe of weld position is utilizedf AInstead of the equivalent structure stress at toe of weld position
ΔSS A, N=54571.641 in the embodiment;
13, the service life N obtained in step 12 is unsatisfactory forRequirement, f is that safety is in formula
It counts, f=1.2, N (design)=80000 in the present embodiment, therefore cannot meet the requirements, keeping S1/S2The constant base of ratio
Increase the Size of welds S along loading plate on plinth simultaneously1With the Size of welds S along non-bearing plate2, it is denoted as S1 *And S2 *, S1 *=15,
S2 *=18, utilize S1 *Instead of S1, utilize S2 *Instead of S2Rebuild mould;
14, step 2 is repeated to 13, solves to obtain Δ σf A=154.6278, Δ Ss B=116.7138,The inspection in step 10 cannot be met, therefore reduce the Size of welds S along non-bearing plate2, it is denoted as S2",
S2"=10, at this time S1It remains unchanged, S1=15, then utilize S2" replace S2Again it models and calculates, Δ σ can be obtainedf A=
143.4238 Δ Ss B=138.3129, meetMathematic(al) expectation N=98317 meets
Requirement;
15, mathematic(al) expectation N that step 14 obtains in the embodiment meetsRequirement, therefore
It is not required to carry out the cycle in the step;
16, mathematic(al) expectation N meets at this timeThen S1=15mm, S2=10mm is just that aluminium closes
Golden cruciform joint works as t=10mm, T=10mm, e=0.07mm, α=0.005236rad, p=0mm, P=90MPa, f=1.2, N
(design)=80000 the optimal Size of welds in the case of, that is, complete cruciform joint toe of weld and weld seam in the embodiment etc.
Carrying design.
Claims (4)
1. realizing the equal bearing methods of cruciform joint toe of weld and weld seam using structural stress method, it is characterised in that utilize structural stress
Method realizes that the equal bearing methods of cruciform joint toe of weld and weld seam are completed according to the following steps:
One, establish or change cruciform joint model:Under the conditions of stress ratio R=0, cruciform joint two dimensional model, non-bearing plate are established
Thickness T and carrying plate thickness t is according to the determination of Practical Project demand, S1For along the Size of welds of loading plate, S2For along non-bearing plate
Size of welds, and S1Initial value it is equal with t, S2Initial value it is equal with t, p is fusion penetration;Stress ratio R isWherein
σminFor minimum external applied load, σmaxFor maximum external applied load;
Two, 1., the lateral nodal force f of extraction toe of weld position specified cross-sectionxiWith longitudinal nodal force f of toe of weld position specified cross-sectionyi,
Toe of weld position specified cross-section is toe of weld position along loading plate plate thickness direction section;2., extraction root of weld position specified cross-section
Lateral nodal force FxiWith longitudinal nodal force F of root of weld position specified cross-sectionyi, root of weld position specified cross-section is root of weld position
With the section in loading plate direction in 90 °;
Three, 1., according to formula (1) toe of weld section membrane stress σ is calculatedm,
σ in formula (1)mFor toe of weld section membrane stress, l is toe crack extensions path length, and
2., toe of weld section flexure stress σ calculated according to formula (2)b,
σ in formula (2)bFor toe of weld section flexure stress, yiFor the distance between toe of weld position section interior joint i and node 1, section
Point 1 is toe of weld position stress concentration point;
3., toe of weld cross-sectional shear power τ calculated according to formula (3)T,
τ in formula (3)TFor toe of weld cross-sectional shear power;
Four, the equivalent structure stress Δ S at toe of weld position is calculated according to formula (4)S A,
Δ S in formula (4)s AFor the equivalent structure stress at toe of weld position, m is material constant, the m=3.6 of aluminium alloy cruciform joint,
The m=3.13 of steel cruciform joint,For load flex than dimensionless function;
Aluminium alloy cruciform joint is calculated according to formula (5)Steel cruciform joint is calculated according to formula (6)
R is toe of weld bend ratio in formula (5) and formula (6), and r is calculated according to formula (7),
When there are axis deviations with angular deformation for test specimen, it is modified using formula (8), obtains the equivalent of revised toe of weld position
Structural stress Δ σf A;
Δ σ in formula (8)f AFor the equivalent structure stress of revised toe of weld position, P is plus load;
K is calculated according to formula (9)e,
L is test length in formula (9), i.e., test specimen total length subtracts clamping length, and Lc is additional bending moment action length, Lc=L/
2-T/2, e are the axis deviation value of cruciform joint,
K is calculated according to formula (10)α,
α is cruciform joint angular deformation radian value in formula (10);
Five, root of weld position 1., according to formula (11) is calculated along the membrane stress σ for assuming cracking angles theta sectionm(θ),
σ in formula (11)m(θ) is membrane stress of the root of weld position along hypothesis cracking angles theta section, and θ is that the hypothesis of root of weld position cracks
Angle indicates to assume that the angle that cracking face is formed by with loading plate, l (θ) are that crackle is long along cracking angles theta root crack extensions path
Degree;
L (θ) is calculated using formula (12),
2., root of weld position calculated along the bending stress σ for assuming cracking angles theta section according to formula (13)b(θ),
σ in formula (13)b(θ) is root of weld position along the bending stress for assuming cracking angles theta section, YiTo be saved in the section of root of weld position
The distance between point i and node 1, node 1 are root of weld position stress concentration points;
3., root of weld position calculated along the shearing force τ for assuming cracking angles theta section according to formula (14)T(θ),
τ in formula (14)T(θ) is root of weld position along the shearing force for assuming cracking angles theta section;
Six, root of weld position is calculated along the equivalent structure stress Δ S for assuming cracking angles theta section according to formula (15)S(θ)B,
Δ S in formula (15)S(θ)BThe equivalent structure stress in cracking angles theta section is assumed for root of weld position edge,For load
The dimensionless function of bend ratio;
Aluminium alloy cruciform joint is calculated according to formula (16)Steel cruciform joint is calculated according to formula (17)
R (θ) is root of weld bend ratio in formula (16) and formula (17);
R (θ) is calculated according to formula (18),
Seven, derivation is carried out to θ using formula (15) using method of derivation, finds out θ and existsBetween Δ Ss(θ)BMaximum value, note
For Δ Ss B, Δ Ss BThe as equivalent structure stress at root of weld position, Δ Ss BCorresponding angle, θ is opening when root of weld failure occurs
Split angle predicted value;
Eight, by the equivalent structure stress Δ S at toe of weld positionS AWith root of weld position equivalent structure stress Δ Ss BIt is compared, works as test specimen
There are when axis deviation and angular deformation, then the equivalent structure stress Δ σ of revised toe of weld position is utilizedf AInstead of toe of weld position etc.
Imitate structural stress Δ SS AWith root of weld position equivalent structure stress Δ Ss BIt is compared, and is carried outInspection, ifThen increase the Size of welds S along non-bearing plate2, it is denoted as S2', then utilize S2' replace S2Again it models;
Nine, step 2 is repeated to eight, until
Ten, the result of calculation obtained using step 9 is carried outInspection, if being unsatisfactory forThen reduce edge
The Size of welds S of non-bearing plate2, it is denoted as S2", then utilize S2" replace S2Rebuild mould;
11, step 2 is repeated to ten, until
12, the N calculating of connector mathematic(al) expectation value carried out to the result of calculation that is obtained using step 11, and by connector mathematic(al) expectation
Value N and projected life N (design) is compared;
The connector mathematic(al) expectation value N of aluminium alloy cruciform joint is calculated according to formula (19), and the connector of steel cruciform joint calculates the longevity
Life value N is calculated according to formula (20);
N is connector mathematic(al) expectation value, Δ S in formula (19) and formula (20)S AFor toe of weld position equivalent structure stress, when test specimen is deposited
In axis deviation and angular deformation, the equivalent structure stress Δ σ of revised toe of weld position is utilizedf AInstead of the equivalent knot at toe of weld position
Structure stress Δ SS A;
If 13, being unsatisfactory forF is safety coefficient in formula, is keeping S1/S2It is same on the basis of ratio is constant
Size of welds Ss of the Shi Zeng great along loading plate1With the Size of welds S along non-bearing plate2, it is denoted as S1 *And S2 *, utilize S1 *Instead of S1, profit
Use S2 *Instead of S2Rebuild mould;
14, step 2 is repeated to 13, until
If 15, being unsatisfactory forWhen, keeping S1/S2Reduce simultaneously along carrying on the basis of ratio is constant
The Size of welds S of plate1With the Size of welds S along non-bearing plate2, it is denoted as S1 **And S2 **, utilize S1 **Instead of S1, utilize S2 **Instead of
S2Rebuild mould;
16, step 2 is repeated to 15, untilThat is N meetsIt is complete
It is designed at the equal carryings of cruciform joint toe of weld and weld seam.
2. the equal bearing methods of cruciform joint toe of weld and weld seam, spy are realized using structural stress method as described in claim 1
It levies and is in step 1 to be more than 0 as stress ratio R, formula (4) is replaced with into formula (21);Formula (15) is replaced with into formula
(22),
3. the equal bearing methods of cruciform joint toe of weld and weld seam, spy are realized using structural stress method as described in claim 1
It levies and is in step 1 to be less than 0 as stress ratio R, formula (4) is replaced with into formula (23);Formula (15) is replaced with into formula
(24),
4. it is according to claim 1,2 or 3 using structural stress method realize cruciform joint toe of weld and weld seam etc. loading sides
Method, it is characterised in that method of derivation is replaced using the method for exhaustion in step 7, with step-lengthExhaustive sectionInterior Δ SS(θ)B,
Find Δ Ss(θ)BMaximum value, be denoted as Δ Ss B。
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Cited By (2)
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| CN111604614A (en) * | 2020-04-30 | 2020-09-01 | 哈尔滨工业大学 | Weld joint shape design method enabling amplitude-variation fatigue performance of welding joint to be identical to that of base metal |
| CN113165674A (en) * | 2018-12-05 | 2021-07-23 | 日本制铁株式会社 | Method for evaluating stress of welded portion of bogie frame for railway vehicle |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN113165674A (en) * | 2018-12-05 | 2021-07-23 | 日本制铁株式会社 | Method for evaluating stress of welded portion of bogie frame for railway vehicle |
| CN111604614A (en) * | 2020-04-30 | 2020-09-01 | 哈尔滨工业大学 | Weld joint shape design method enabling amplitude-variation fatigue performance of welding joint to be identical to that of base metal |
| CN111604614B (en) * | 2020-04-30 | 2021-12-24 | 哈尔滨工业大学 | Weld joint shape design method enabling amplitude-variation fatigue performance of welding joint to be identical to that of base metal |
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