CN101850470A - Interlocking double vertical explosion welding protection device - Google Patents

Abstract

The invention relates to an interlocking-type double-vertical explosive welding permanent protecting device, saving 2/3 explosive load, greatly decreasing the processing cost, lessening the adverse influence of most impact waves on surrounding environment, satisfactorily solving the explosion filed problem of explosive welding and easily forming a standard process flow. By the overall design and the computer simulation of the protecting device, the protection structure and the size of a double-vertical exploder are acquired. The protecting device not only can guarantee that two welded composite plates do not deform seriously, but also can be repeatedly used.

Description

Interlocking double vertical explosion welding protection device

technical field

The present invention relates to an interlocking double vertical explosion welding protection device. During the double vertical explosion welding process, the protection device can not only make the two composite plates tend to be in a static and controllable state instantaneously, so as not to produce large deformation Destroying, and further reducing the impact of blast shock waves on the surrounding environment, belongs to the field of explosive welding and metal material comprehensive technology.

Background technique

In order to make full use of the energy of explosives, reduce the adverse impact of shock waves on the surrounding environment, and form a stable production process, the author invented a double-vertical explosive welding method through theoretical analysis and experimental research. Two invention patents have been applied for this method and the charging process.

As shown in accompanying drawing 2, the shock wave produced by the detonation of the explosive 4 after the detonation of the detonator causes the two double panels (3 and 5) erected on the left and right sides to bend and plastically deform, and are respectively parallel to the two erected panels on both sides. The base plates (1 and 7) collide and are welded, and the two composite plates after welding do not move downward to collide with the foundation, but move to both sides.

Compared with the prior parallel explosive welding method, the Shuangli explosive welding method has the following three important advantages:

(1) Energy saving and emission reduction, cost reduction (can save 2/3 charge), and increase efficiency.

The double-vertical explosive welding method changes the open explosive welding structure of the parallel method into a closed welding structure, and the energy of the explosives is fully utilized. With the same amount of charge, the parallel method successfully welds one composite plate, while the double method successfully welds two pieces of the same size composite panels. In addition, in the double-stand explosion method, since the detonation wave propagates and acts between the rigid walls of the double panels, the superimposed effect of the detonation load makes it save a part of the charge compared with the current parallel explosion method. The experiment also proves that the double-vertical explosive welding method can save at least 2/3 of the charge. This greatly reduces the consumption of explosive energy and gas emissions, not only saves energy and protects the environment, but also greatly reduces processing costs and improves the operational efficiency of explosive welding.

(2) Reduce the explosive welding shock wave and improve the feasibility of explosive welding production.

In the Shuangli explosive welding method, the two composite panels after welding do not move downward to collide with the foundation, but move to both sides. If a permanent protective structure is designed on both sides (as shown in Figure 3), the composite plates and protective structures on both sides will greatly reduce the destructive effect of the explosive welding shock wave on the surrounding environment, and basically solve the environmental protection problem of explosive welding. Improved explosive welding feasibility production issues. In addition, the reduction in the amount of medicine also reduces the negative impact on the surrounding environment.

(3) The parameters are easy to control, it is easy to form a standardized mechanized production mode, and the product quality is easy to control.

After the Shuangli explosion, the composite board moves to both sides, and the protective structures on both sides are fixed devices formed through theoretical simulation calculations and multiple tests in advance, so that the successfully welded composite board will not produce large plastic deformation and Defects such as cracks not only reduce the follow-up processing of the clad plate, but also improve the welding quality of the clad clad plate.

In the Shuangli explosion method, the installation parameters such as the base doubler plate gap and the distance between the two doubler plates (that is, the charge thickness) are all installed in the production workshop in advance, which ensures the stability of charge parameters and installation parameters. It is not only conducive to improving the quality of explosive welding, but also changes the manual operation mode of the current explosive welding method into a mechanical operation mode.

In addition, the existing parallel blasting method is due to fully exposed charges and field operations, so if it meets rainy weather, the explosive welding production will not be carried out. In the Shuangli explosion method, the charge is almost completely enclosed, and most of the operation process is completed in the production workshop, so even if it encounters rainy weather, the operation can still be carried out. Therefore, the Shuangli explosion method is convenient to form a whole set of technological process, form a standardized operation mode, and easily form a standard technological process.

Although the Shuangli explosion method has obvious advantages, and the applicant has also solved the charge parameters and installation process problems of Shuangli explosion welding, there is still a key point for this method to replace the existing method and enter industrialization and large-scale application. Problem - The protection problem on both sides of the composite board needs to be solved.

Since the clad plate still has a considerable flight speed after explosive welding, if the protective structure on both sides is not accurately calculated and simulated, it will not only destroy the clad plate that has been successfully clad, but also make the production of explosive welding very expensive. risks and uncertainties. Therefore, by studying the movement law of the composite plate after welding by the double vertical explosive welding method, and studying the mechanism and deformation law between the composite plate and the protective structure, a permanent protective structure on both sides that can be used multiple times is finally designed.

Contents of the invention

The purpose of the present invention is to optimize the design of a reusable interlocking Shuangli explosive welding protection device through theoretical calculation, numerical simulation and field tests, so that the Shuangli explosive welding method can be put into industrial production, and finally it can save 2 /3 explosives and further reduce the adverse impact of the shock wave on the surrounding environment.

Technical solution of the present invention:

1. Overall scheme design of interlocking protection device

In the Shuangli explosive welding device, since the composite board still has a considerable movement speed to the outside after welding, two protective plates must be installed on the outside of the two pairs of base plates to prevent the flight movement of the composite board.

In the process of collision between the composite plate and the protective plate, in order to ensure that both will not produce large deformation and damage, the protective plate must have sufficient rigidity and strength in terms of material selection and thickness design.

At the same time, the protective plate should keep the composite plate in a static state immediately after the impact, and the protective plate must still be in a fixed state after being hit by the composite plate. The present invention designs two square hoops at the upper and lower positions of the periphery of the two protective plates. , the two hoops are connected with the two protective plates by electric welding or screws. Once the composite plate collides with the protective plate from top to bottom, the two protective plates have a tendency to move outward from top to bottom, and their loads act on the two sides connecting the hoop and the protective plate respectively, because the loads on both sides are symmetrical If yes, the hoop plays the role of locking the two protective plates, so that the two protective plates and the upper and lower hoops connected to them remain fixed and static, thereby preventing the flight movement of the two composite plates. Since the final load acts on the two hoops, the material selection and section design of the hoops must ensure that they have sufficient strength to overcome the flight energy of the composite plate.

2. Computer simulation of interlock protection device

2.1 Model establishment

The first step in finite element analysis using ANSYS/LS-DYNA software is to establish a solid model. The three-dimensional model of explosives, cladding plate, base plate, protective plate and hoop is established by solid modeling method. From the perspective of exhaust, the thicker the cladding plate and the larger the area, the lower the detonation velocity of the explosive should be, and the axisymmetric detonation method needs to be adopted. Since the models of explosives, cladding plates, base plates, protective plates and hoops are axisymmetric, only 1/2 of them are modeled and analyzed to simplify the calculation. When performing finite element analysis, ANSYS software should simplify the analyzed object as much as possible in order to reduce computer time and save computer resources. Simplification is carried out, so the solid model can be simplified into a four-part cuboid structure. As shown in Figure 1, the first part is the explosive (ammonium nitrate emulsion explosive), the second part is the cladding plate (304 stainless steel), the third part is the base plate and the protective plate (Q235B steel), and the fourth part is the hoop (Q235B steel).

2.2 Unit division

Explosives, cladding plates, base plates, fenders and hoops all use 8-node solid164 solid elements. In the finite element model, explosives and air are defined as fluids, which are described by 8-node Euler elements, and the cladding, base plate, protective plate and hoop are described by 8-node Lagrang elements. The number of summary points for the model is 500,000 and the total number of cells is 400,000.

An important problem in explosive welding is to deal with the interaction between fluid and solid. The ALE grid not only maintains the characteristics of the Euler grid but also maintains the characteristics of the Lagrang grid. The ALE algorithm first performs one or several Lagrang time-step calculations. At this time, the cell grid deforms with the material flow, and then performs the ALE time-step calculation: firstly, the deformed object boundary conditions are maintained, and the internal cells are re-meshed. The topological relationship of the mesh remains unchanged; then the element variables (density, energy, stress tensor, etc.) and node velocity vectors in the deformation are transported to the new mesh after redivision. With this method, the fluid mesh and the solid mesh can be conveniently coupled to deal with the interaction of structures under various complex load conditions.

2.3 Material model

(1) Explosives

The detonation process of explosives is a very complex chemical and physical process. The HIGH_EXPLOSIVE_BURN material model in the LS-DYNA program is used to simulate the detonation of advanced explosives. The isentropic expansion process produced by the detonation is described by the JWL equation of state, and the pressure P is

E＝2.5331×10⁷。In the formula, P is the detonation pressure; V is the relative volume of the explosive, V=v/v ₀ ; E is the initial internal energy of the material per unit volume; A, B, R ₁ , R ₂ , is a dimensionless parameter. The detonation gamma equation of explosives is used to fit the results: the JWL equation of state is an empirical equation of state used to describe the explosion products, and it is applicable to various condensed explosives. Ammonium nitrate emulsion explosive parameters: explosive density ρ=750kg.m ^-3 , explosion velocity C=3000m.s ^-1 , A=20.275×10 ¹⁰ , B=4.39×10 ⁹ , R ₁ =5.3, R ₂ =1.2,

E=2.5331×10 ⁷ .

(2) air

The air detonation pressure is described by a null material (Null) model and a linear polynomial (Linear_Polinominal) equation of state. In EOS_LINEAR_POLYNOMIAL, the keyword is used to define the coefficients of the linear polynomial equation of state. By defining E0 and V0, the initial thermodynamic state of the material can be initialized.

The linear polynomial equation of state expresses the linear relationship of internal energy per unit initial volume, and the pressure value is given by

P＝C ₀ +C ₁ μ+C ₂ μ ² +C ₃ μ ³ +(C ₄ +C ₅ μ+C ₆ μ ² )E (2)

In the formula, C ₀ , ..., C ₆ are constants, and if μ<0 in the formula, the two items of C ₂ μ ² and C ₆ μ ² are zero. in

$\mathrm{<span\; class="notranslate">\; \&mu;</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; \&gamma;</span>}}{\mathrm{<span\; class="notranslate">\; V</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

In the formula, V is the relative volume; γ is the unit calorific value rate. Then the pressure is determined by

$\mathrm{<span\; class="notranslate">\; P</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&gamma;</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>\frac{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}{{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}\mathrm{<span\; class="notranslate">\; E.</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

Under standard atmospheric pressure, the air density is 1.2929kg.m ^-3 .

(3) Double board

The Johnson-Cook model can better reflect the change of mechanical properties of materials under the condition of explosive welding with high strain rate, that is, the yield stress is a function of plastic strain, strain rate and temperature. In explosive welding, the deformation rate of metal can reach 10 ⁶ ～10 ⁷ s ^-1 , and instantaneous high pressure and high temperature are generated. It is difficult for general material models to reflect the mechanical properties of materials at such high strain rates. The Johnson-Cook model equation is

${\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; A</span>}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; B\&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}^{\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; C</span>}\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; no</span>}\frac{\stackrel{<span\; class="notranslate">\; \&CenterDot;</span>}{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}}{{\stackrel{<span\; class="notranslate">\; \&Center\; Dot;</span>}{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; T</span>}}^{<span\; class="notranslate">\; *</span>\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

为实际应变率；

为参考应变率；T为温度；T_m为材料熔点；T_r为室温；A、B、n、C、m为材料常熟。In the formula, ε _p is the actual plastic strain;

is the actual strain rate;

is the reference strain rate; T is the temperature; T _m is the melting point of the material; T _r is the room temperature; A, B, n, C, m are the material constants.

For 304 stainless steel cladding plate, the GRUNEISEN state equation is used to describe its dynamic performance

$\mathrm{<span\; class="notranslate">\; P</span>}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; [</span>\frac{{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; C</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; \&mu;</span>}<span\; class="notranslate">\; [</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&gamma;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; \&mu;</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; aa\&mu;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; \&mu;</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; S</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; \&mu;</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; /</span>{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; \&mu;</span>}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; ]</span><span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&gamma;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; aa\&mu;</span>}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; E.</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$

Among them, S ₁ =1.33, S ₂ =0.00, S ₂ =1.5, γ ₀ =2.15, C=4500, aa=0.46.

(4) Base plate, fender and hoop

The base plate, fender and hoop adopt the dynamic strengthening model (PLASTIC-KINEMATIC). The dynamic mechanical properties of materials are described by the Cowper-Symonds method with the influence of strain rate, and the flow stress σ _y is calculated by the following formula

${\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; \&lsqb;</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>\frac{\stackrel{<span\; class="notranslate">\; \&Center\; Dot;</span>}{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}}{\mathrm{<span\; class="notranslate">\; CC</span>}}<span\; class="notranslate">\; )</span>}^{\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; PP</span>}}}<span\; class="notranslate">\; \&rsqb;</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&beta;E</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}}{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; eff</span>}}^{\mathrm{<span\; class="notranslate">\; p</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 7</span>}<span\; class="notranslate">\; )</span>$

In this paper, Q235B is used for the substrate, protective plate and hoop, its density ρ=782kg.m ^-3 , elastic modulus E=210GPa, σ ₀ , E _p are 235Mpa and 2.0Gpa respectively, CC and PP are 0.0001 and 20 respectively ;β=1.0.

3. Simulation results

According to the simulation calculation and test results, it is finally determined that the material of the protective plate is ordinary steel, the thickness of the protective plate is greater than 50mm, and its height is 10mm higher than that of the doubler plate.

It is finally determined that the material of the hoop is ordinary steel, its cross-section is larger than 50mm×50mm, and the distance between the two hoops is 200mm.

Description of drawings

Accompanying drawing 1 is a schematic diagram of a double-vertical explosive welding device.

In the figure, 1 is explosive, 2 is A doubler plate, 3 is B doubler plate, 4 is A gap, 5 is B gap, 6 is A base plate, 7 is B base plate, 8 is A protective plate, 9 is B protective plate , 10 is the basis.

Accompanying drawing 2 is the schematic diagram of the interlocking dual vertical explosion welding protective device.

11 among the figure is the A protective plate, 12 is the B protective plate, 13 is the upper hoop, and 14 is the lower hoop.

Detailed ways

Example 1

Referring to attached drawing 1, explode two pairs of stainless steel-steel composite plates, the specification of which is 1500×2000×(6+20), containing 38 kg of explosives. After explosive welding, the two composite plates are in the interlocking protective device, and the composite rate is 100%. , the protective device is not deformed and damaged, and can still be used repeatedly.

Claims (3)

1. The interlocking double vertical explosion welding protection device is characterized in that two protective plates are vertically arranged on the two outer sides of the two base plates, and two square hoops are connected up and down on the outer edges of the two protective plates. 2. Two protective plates according to claim 1, characterized in that by computer simulation, the material of its protective plate is common steel, the thickness of its protective plate is greater than 50mm, and its height is higher than the compound plate by 10mm. . 3. The hoop according to claim 1, characterized in that its material is ordinary steel through computer simulation calculation, the cross-section is larger than 50mm×50mm, and the distance between the two hoops is less than 200mm.

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