CN101590567A - Method for calculating upper limit and lower limit of explosive welding and charging thickness window - Google Patents

Abstract

The present invention proposes the new criterion of determining sheet metal explosive welding and charging thickness window upper and lower bound: in the explosive welding process, it is crooked that the explosive load that explosive detonation produces must make compound plate produce, but can not make compound plate crack or destroy, could realize successfully welding.The upper and lower bound computational methods of explosive welding and charging thickness window have been formed in view of the above, can directly draw the upper and lower bound value of charge depth by this method, not only be suitable for the explosive welding engineering and use, and provide convenient method and theoretical foundation for special material explosive welding and charging parameter.

Description

Method for calculating upper limit and lower limit of explosive welding and charging thickness window

Technical field

What the present invention relates to is that the sheet metal explosive welding and charging thickness window is a kind of computational methods of upper and lower bound dose.Belong to the explosion welding technique field.

Background technology

Explosion welding technique and explosive composite material be widely used in oil, chemical industry, shipbuilding, electric power, Aeronautics and Astronautics, salt manufacturing, system alkali, metallurgy, atomic energy, digging, transportation, and every field such as machine-building among.

ShaoBing Huang, Zhang Kai etc. are subjected to the inhibitory action of metal visco-plasticity or viscosity possibly according to base, the formation that reenters jet during the compound plate sharp impacts, by considering that metal viscous force momentum equals to form the momentum that reenters jet in the unit interval, obtained explosive welding and formed the minimum impingement angle β that reenters jet _cWhen impingement angle β big more, impact velocity v then _pBig more, the scope of higher-pressure region is also big more, and the interface wave distortion is serious more, even melting phenomenon occurs, causes that faying face intensity descends this β _dDo not allow the upper bound condition that occurs when being called explosive welding.The new grade of Wang Yu carried out Computer Simulation research to Double Metal Explosive Welding Window, but still research is the explosive welding dynamic parameter.

The above-mentioned upper limit that obtains according to impingement angle and impact velocity (superfusion does not appear in the interface) and lower limit (interface generation jet) be the necessary condition of success welding just, rather than necessary and sufficient condition.And two dynamic parameters of the just explosive welding that relates to of this bound, it is very inconvenient to use for engineering.Practical application is very necessary for engineering how to seek a kind of upper and lower bound of explosive welding and charging thickness window.And for the fragile material explosive welding, its charge depth upper limit is generally less than the interface and produces the fusing upper limit, and therefore the definite successful explosive welding for fragile material for the explosive welding and charging thickness upper limit seems particularly important.In addition, it is very narrow that some material can weld window, therefore even more important for definite method of upper and lower bound.

The present invention has proposed the computational methods of a sheet metal explosive welding and charging thickness window upper and lower bound by theoretical and experiment.

In the explosive welding process, compound plate at first must produce crooked, and secondly compound plate can not crack or destroy, and promptly the detonation load must satisfy following two most important condition and could realize successfully welding:

The minimum moment of flexure that blast load produced at first must surpass the dynamic yield limit moment of flexure of material, makes compound plate produce the bending distortion, could satisfy the primary condition of explosive welding compound plate and substrate angular impact.This is successful explosive welding and charging thickness lower limit.

The maximal bending moment that blast load produced must be less than the dynamic tension ultimate bending moment of material, and compound plate is unlikely to be cracked or destroy, and could satisfy the stable condition of explosive welding compound plate and substrate angular impact, thereby just might obtain effective weld interface.This is the explosive welding and charging thickness upper limit.

Summary of the invention

1, the moment of flexure of compound plate surface detonation load generation

By the explosive detonation characteristic, the load that can draw explosive welding compound plate upper surface distributes as shown in Figure 1, and its welding parameter as shown in Figure 2.

If do not consider the pressure distribution (in fact be to consider, but only be concerned about the pressure in detonation product district here) of chemistry of explosives reaction zone, then the pressure p of detonation wave head so can put aside _HFor:

$p_H=\frac{1}{1+{\mathrm{\γ}}_H}{\mathrm{\ρ}}_0{D}^2---\left(1\right)$

Wherein, γ ₀Be the polytropic index of explosive, γ _HBe the polytropic index of detonation wave head, ρ ₀Be explosive density, D is an explosion velocity of explosive.If charge depth is δ, getting the detonation wave head is the origin of coordinates, is positive direction left, the sparse effect in the scope of freedom in the consideration, and then detonation product district pressure p (x) is:

$\frac{p\left(x\right)}{p_H}={\left[\cos \left(\sqrt{\frac{{\mathrm{\γ}}_0-1}{{\mathrm{\γ}}_0+1}}{\mathrm{tg}}^{-1}\frac{x}{\mathrm{\δ}}\right)\right]}^{\frac{{2\mathrm{\γ}}_0}{{\mathrm{\γ}}_0-1}}---\left(2\right)$

When $\frac{x}{\mathrm{\δ}}=0$ The time, promptly at detonation wave head place, $\frac{p\left(x\right)}{p_H}=1;$ When

During increase,

With

Degree decay rapidly with cosine function.In conjunction with the result of high-speed photography experiment repeatedly, might as well think that explosive is approximately the EFFECTIVE RANGE (l) of compound plate:

$l=\frac{s}{\mathrm{tg\β}}=\mathrm{k\δ}---\left(3\right)$

S is a distance between plates in the formula, usually, and k=1.5～3.0.

Parallel device is adopted in general explosive welding, at this moment:

$v_p=2D\sin \frac{\mathrm{\β}}{2}---\left(4\right)$

Work as v _pMove to the C point by the B point, and v _cThen move to the C point by the A point, so have:

$v_c=\frac{v_{\mathrm{<figure-callout\; id="2"\; label="p"\; filenames="A2009100336080009H1.png,A2009100336080009H2.png"\; state="\{\{state\}\}">p</figure-callout>}}}{2\sin \frac{\mathrm{\&beta;}}{2}}=D---\left(5\right)$

Comprehensive 1 to 5 formula, by calculate can in the hope of: $p_0\&ap;(\frac{3}{10}~\frac{3}{5})p_H---\left(6\right)$

In sum, can be clearly following 2 points:

(1) because blast load pressure p (x) is a function that descends rapidly, and the effective range of blast load pressure is l=k δ, and the actuating pressure on point of impingement compound plate surface $p_0\&ap;(\frac{3}{10}~\frac{3}{5})p_H.$

(2) because CD section compound plate is subjected to the pressure effect of detonation wave head, its acceleration maximum, and speed is 0, and therefore, the CD section of compound plate can be considered canned paragraph, and the suffered load of this section is the support reaction of stiff end, and the C point is a stiff end; BC section compound plate (except that the B point of seam just) then can be considered free section, and point infinitely approaching with the B point, that be about to collision then is a free end; So, stand detonation pressure produce flexural deformation and have that the BCD section compound plate of acceleration just can be considered that an end is fixed, end cantilever beam freely, as shown in Figure 3.

Can obtain the moment of flexure that the load on the BC section compound plate is ordered to C thus:

$M_{\max }=\frac{1}{3}{q}_H{\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="A2009100336080009H1.png,A2009100336080009H2.png"\; state="\{\{state\}\}">l</figure-callout>}}^2+\frac{1}{6}{q}_x{l}^2---\left(7\right)$

Q wherein _x=p (x) b=p (x) (b is a unit length).

And the pressure p of detonation wave head _HFor:

$p_H=\frac{1}{1+{\mathrm{\&gamma;}}_0}{\mathrm{\&rho;}}_0{D}^2---\left(8\right)$

Can be got by formula (2), then detonation product district pressure p (x) is:

$P\left(x\right)=p_H{\left[\cos \left(\sqrt{\frac{{\mathrm{\&gamma;}}_0-1}{{\mathrm{\&gamma;}}_0+1}}{\mathrm{tg}}^{-1}\frac{x}{\mathrm{\&delta;}}\right)\right]}^{\frac{2{\mathrm{\&gamma;}}_0}{{\mathrm{\&gamma;}}_0-1}}---\left(9\right)$

Can get (8) and (9) formula substitutions (7):

$M_{\max }=\frac{1}{3}{\mathrm{<figure-callout\; id="2"\; label="p\; H\; l"\; filenames="A2009100336080009H1.png,A2009100336080009H2.png"\; state="\{\{state\}\}">p</figure-callout>}}_H{l}^{}{}^2+\frac{1}{6}{p}_H{\left[\cos \left(\sqrt{\frac{{\mathrm{\&gamma;}}_0-1}{{\mathrm{\&gamma;}}_0+1}}{\mathrm{tg}}^{-1}\frac{l}{\mathrm{\&delta;}}\right)\right]}^{\frac{{2\mathrm{\&gamma;}}_0}{{\mathrm{\&gamma;}}_0-1}}{\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="A2009100336080009H1.png,A2009100336080009H2.png"\; state="\{\{state\}\}">l</figure-callout>}}^2$

$=\frac{1}{6(1+{\mathrm{\&gamma;}}_H)}{\mathrm{\&rho;}}_0{D}^2{l}^2[2+{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="A2009100336080009H1.png,A2009100336080009H2.png"\; state="\{\{state\}\}">cos</figure-callout>}}^{\frac{2{\mathrm{\&gamma;}}_0}{{\mathrm{\&gamma;}}_0-1}}\left(\sqrt{\frac{{\mathrm{\&gamma;}}_0-1}{{\mathrm{\&gamma;}}_0+1}}{\mathrm{tg}}^{-1}\frac{l}{\mathrm{\&delta;}}\right)]---\left(10\right)$

γ in the formula ₀Be the polytropic index of explosive, D is an explosion velocity of explosive, and δ is a charge depth.

2, the dynamic beaming resistance limit moment of flexure of compound plate material

σ _sThe static yield strength of expression compound plate, the dynamic yield strength of compound plate material is σ _d(σ _d=30 σ _s).Might as well establish compound plate and be in the perfect plasticity state, then compound plate produces ultimate bending moment, as shown in Figure 4.Can draw the dynamic limit moment of flexure W of compound plate under Explosion Loading _m:

$W_m={\mathrm{\&sigma;}}_d\frac{h}{2}\frac{\mathrm{<figure-callout\; id="2"\; label="h"\; filenames="A2009100336080009H1.png,A2009100336080009H2.png"\; state="\{\{state\}\}">h</figure-callout>}}{2}=\frac{1}{4}{\mathrm{\&sigma;}}_{\mathrm{<figure-callout\; id="2"\; label="d\; h"\; filenames="A2009100336080009H1.png,A2009100336080009H2.png"\; state="\{\{state\}\}">d</figure-callout>}}{h}^{}{}^2=\frac{15}{2}{\mathrm{\&sigma;}}_s{h}^2---\left(11\right)$

Wherein h is a compound plate thickness.The tensile strength that surpasses material as blast load will make material production destroy, and in like manner, this compound plate produces the dynamic limit moment of flexure W that breaks under Explosion Loading _pFor:

$W_p=\frac{15}{2}{\mathrm{\&sigma;}}_b{h}^2---\left(12\right)$

3, upper limit and lower limit of explosive welding and charging thickness window

In the explosive welding process, compound plate at first must produce crooked, and secondly compound plate can not produce destruction, and promptly blast load must satisfy following two conditions and could realize successfully welding:

(1) maximal bending moment that blast load produced at first must surpass the dynamic yield limit moment of flexure of material, makes compound plate produce the bending distortion, could satisfy the primary condition of explosive welding compound plate and substrate angular impact.

That is: M _Max〉=W _m(13)

(2) maximal bending moment that blast load produced must not cause compound plate to produce and destroy less than the dynamic tension ultimate bending moment of material, could satisfy the stable condition of explosive welding compound plate and substrate angular impact, thereby just might obtain effective weld interface.That is:

M _max≤W _p (14)

(10) and (12) formula substitutions (13) Shi Kede:

$\mathrm{\&delta;}\&GreaterEqual;\mathrm{<figure-callout\; id="1"\; label="lctg"\; filenames="A2009100336080009H1.png,A2009100336080009H2.png"\; state="\{\{state\}\}">lctg</figure-callout>}\frac{1}{\mathrm{\&omega;}}\arccos \sqrt[m]{\frac{45{\mathrm{\&sigma;}}_s{h}^2(1+{\mathrm{\&gamma;}}_H)}{{\mathrm{\&rho;}}_0{D}^2{l}^2}-2}---\left(15\right)$

In the formula, $m=\frac{2{\mathrm{\&gamma;}}_0}{{\mathrm{\&gamma;}}_0-1};$ $\mathrm{\&omega;}=\sqrt{\frac{{\mathrm{\&gamma;}}_0-1}{{\mathrm{\&gamma;}}_0+1}}.$

Like this, just obtained the expression formula of powder charge critical thickness δ, its minimum of a value is powder charge lower limit δ _Min, this formula is used very convenient for engineering.Certainly, (compound plate of h≤4mm) according to the result of calculation of following formula, may occur: δ for thinner thickness _Min＜δ q.(δ in the formula _qCritical Initiation thickness for explosive) situation, so, for guaranteeing reliable initiation, also to limit condition a: δ _Min〉=δ _qIn like manner: (10) and (12) formula substitutions (14) Shi Kede:

$\mathrm{\&delta;}\&le;\mathrm{<figure-callout\; id="1"\; label="lctg"\; filenames="A2009100336080009H1.png,A2009100336080009H2.png"\; state="\{\{state\}\}">lctg</figure-callout>}\frac{1}{\mathrm{\&omega;}}\arccos \sqrt[m]{\frac{45{\mathrm{\&sigma;}}_b{h}^2(1+{\mathrm{\&gamma;}}_H)}{{\mathrm{\&rho;}}_0{D}^2{l}^2}-2}---\left(16\right)$

Its maximum is charge depth upper limit δ _Max

Description of drawings

Accompanying drawing 1 is an explosive welding load action schematic diagram; Accompanying drawing 2 is compound plate three different position views constantly in explosive welding; Accompanying drawing 3 is compound plate Blast Loads sketches; Accompanying drawing 4 is compound plate dynamic limit moment of flexure schematic diagrames.Among the figure 1 is substrate, the 2nd, compound plate, the 3rd, explosive.

The specific embodiment

Embodiment 1

Compound plate is thick 5923 (a kind of import strong corrosion-proof and high-strength degree material) of 2mm, and its yield strength and tensile strength are respectively 360MPa and 780MPa, select 30 for use ^#Emulsion obtains the powder charge bound by computational methods of the present invention and is respectively: 15mm and 55mm.According to the lower limit rule of explosive welding and charging, selecting charge depth for use is 17mm again, and explosive clad plate is superior in quality.

Embodiment 2

Compound plate is the thick TA2 of 2mm, and its yield strength and tensile strength are respectively 245MPa and 465MPa, select 30 for use ^#Emulsion obtains the powder charge bound by computational methods of the present invention and is respectively: 13mm and 38mm.According to the lower limit rule of explosive welding and charging, selecting charge depth for use is 15mm again, and explosive clad plate is superior in quality.

Claims (3)

1, method for calculating upper limit and lower limit of explosive welding and charging thickness window, its feature has proposed the new criterion of definite explosive welding and charging thickness window: explosive load must make compound plate produce bending in the explosive welding process, but can not make compound plate crack or destroy, could realize successfully welding, and obtain the upper and lower bound parameter of explosive welding and charging thickness window thus.

2, the upper limit computational methods of explosive welding and charging thickness window according to claim 1, it is characterized in that the maximal bending moment that blast load produces must be less than the dynamic tension ultimate bending moment of material, compound plate is just unlikely to be cracked or destroys, could satisfy the stable condition of explosive welding compound plate and substrate angular impact, thereby just might obtain effective weld interface, this battering charge thickness is the upper limit of explosive welding and charging thickness window.

3, the lower limit computational methods of explosive welding and charging thickness window according to claim 1, it is characterized in that the minimum moment of flexure that blast load produces at first must be above the dynamic yield limit moment of flexure of material, make compound plate produce the bending distortion, could satisfy the primary condition of explosive welding compound plate and substrate angular impact, this minimum charge depth is successfully the lower limit of explosive welding and charging thickness window.

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