Projectile penetration numerical simulation method

Abstract

The invention discloses a projectile penetration numerical simulation method, which is characterized by comprising the following steps of: selecting a unit type, establishing a unit model, dividing a grid, defining a contact algorithm, defining a boundary condition and applying a load, solving and observing a penetration process. According to the method provided by the invention, the bullet penetration target plate is taken as an example, a specific implementation method of a penetration analysis problem is introduced in detail, the penetration analysis work can be quickly and reliably completed according to the method provided by the invention, and the personnel and economic cost consumed by a bullet penetration test is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgical materials, and in particular relates to a projectile penetration numerical simulation method. Background Art

[0002] At present, armored steel plate manufacturers have been using different methods to continuously optimize and improve the composition, mechanical properties and ballistic performance of high-strength armored steel plates. With the continuous development of armored steel optimized composition design, smelting process and heat treatment process, high-performance armored steels continue to emerge.

[0003] Armor steel has the advantages of high strength, high toughness, high hardness and reasonable hardenability. For more than 100 years, it has been widely used as a structural and protective material for special vehicles such as tanks. Since the advent of armor steel, its bullet penetration process and failure mechanism have been extensively and deeply studied using live-fire shooting assessment, numerical simulation or a combination of the two. Not only has its macroscopic constitutive law been explored from a mechanical perspective, but the influence of organizational changes on its protective performance has also been examined from a microscopic perspective. Furthermore, the comprehensive performance of armor steel has been greatly improved by optimizing the alloy composition, smelting process and heat treatment process.

[0004] Reference 1 evaluated the anti-penetration performance of armored steel / ultra-high performance concrete (UHPC) composite protective structures, and conducted penetration tests and numerical simulation studies on two composite targets. Subsequently, a series of static and dynamic mechanical performance tests were conducted to calibrate the constitutive model parameters of the armored steel material, and a three-dimensional finite element model was established to conduct numerical simulation analysis of the above tests. However, the penetration of deformable projectiles into metal targets and composite targets is a complex process, and no numerical simulation research has been conducted on the target plate failure mode.

[0005] Reference 2 established a temperature-structure-stress coupling constitutive model, which comprehensively considered the volume change caused by solid phase transformation, the change of mechanical properties and the influence of phase transformation plasticity on welding residual stress, studied the armor steel flat plate butt welding, and obtained the temperature, structure and residual stress change law during the armor steel welding thermal cycle. However, the numerical simulation method for the most important anti-ballistic performance of armor steel, namely the bullet penetration problem, was not mentioned.

[0006] Reference 3 studied the penetration behavior of thin-base armor steel under projectile impact through numerical calculation and experimental research, and predicted the ultimate projectile velocity of the target material under projectile impact failure. However, the influence of residual stress of the target material was not considered, and it was assumed that the mechanical properties of the material were uniform, which is obviously different from the actual situation. Summary of the invention

[0007] The purpose of the present invention is to provide a projectile penetration numerical simulation method, so as to realize the rapid and reliable completion of the penetration analysis work and reduce the personnel and economic costs consumed by the bullet penetration test.

[0008] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0009] The present invention provides a projectile penetration numerical simulation method, which includes selecting a unit type → establishing a unit model → meshing → defining a contact algorithm → defining boundary conditions and applying loads → solving → observing the penetration process; specifically, the following steps are included:

[0010] 1) Selection of unit type

[0011] Both the bullet and the target plate are made of SOLID164 units;

[0012] 2) Build a model

[0013] The bullet uses the Type 53 7.62mm WO-109C armor-piercing incendiary bullet. The bullet model is simplified according to the actual size, and simplified to a cylinder with a hemispherical head.

[0014] 3) Grid division

[0015] The target is divided into hexahedral grids;

[0016] 4) Define contact algorithm

[0017] Select the surface-to-surface contact algorithm for anti-ballistic simulation;

[0018] 5) Define boundary conditions and apply loads

[0019] The bullet velocity direction is the normal direction of the target plate. A fixed target plate is defined on the boundary surface, and symmetric boundary conditions are defined to impose translational and rotational constraints on the target plate. The contact between the bullet and the target plate adopts the surface erosion contact algorithm;

[0020] 6) Solution

[0021] Set the analysis time output steps and submit the solution;

[0022] 7) Observe the penetration process

[0023] Post-processing software is used to solve and analyze the projectile-target model.

[0024] Furthermore, in the step 1), the SOLID164 unit is an explicit three-dimensional structural entity unit with 8 nodes, and the nodes have translation, velocity, and acceleration degrees of freedom in the X, Y, and Z directions.

[0025] Furthermore, in step 2), the target plate has a size of 500 mm×500 mm and a thickness of 8 mm; and the initial velocity of the bullet is 820-835 m / s.

[0026] Furthermore, in step 2), taking 1 / 4 of the structure for modeling during simulation can greatly reduce the amount of calculation and shorten the calculation time.

[0027] Furthermore, the initial velocity of the bullet is 820 m / s.

[0028] Compared with the prior art, the beneficial technical effects of the present invention are:

[0029] The penetration of a projectile is a dynamic invasion problem of high impact collision. During the penetration process, elastic deformation, plastic deformation or destruction may occur. Due to the limitations of theoretical level and test conditions, the penetration depth or the stress conditions, velocity and acceleration changes during the invasion process cannot be fully and clearly described. In the research work on projectile invasion, modern numerical calculation methods are used to solve the problem. Numerical simulation of the penetration problem is performed by numerical methods based on finite elements or finite differences. These methods are much better than approximate analysis methods and are less expensive. They are gradually becoming the dominant method. Numerical simulation can make up for the shortcomings of experimental research. The simulation method provided by the present invention can truly reproduce the penetration process of the projectile and conduct more accurate analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be further described below in conjunction with the accompanying drawings.

[0031] Figure 1 A three-dimensional model of a bullet;

[0032] Figure 2 It is a three-dimensional model of the target plate. DETAILED DESCRIPTION

[0033] Example 1

[0034] 1. Selection of unit type

[0035] Both the bullet and the target plate use SOLID164 units. The SOLID164 unit is an explicit three-dimensional structural entity unit with 8 nodes. The nodes have X, Y, Z translation, velocity, and acceleration degrees of freedom.

[0036] 2. Build the model

[0037] The bullet uses the Type 53 7.62mm WO-109C armor-piercing incendiary bullet. The bullet model is simplified according to the actual size and simplified to a cylinder with a hemispherical head. The bullet size and three-dimensional model are as follows Figure 1 shown.

[0038] The target plate size is 500mm×500mm and the thickness is 8mm. The initial velocity of the bullet is 820m / s. When simulating, taking 1 / 4 of the structure for modeling can greatly reduce the amount of calculation and shorten the calculation time.

[0039] 3. Grid division

[0040] The target is divided into hexahedral grids.

[0041] 4. Define the contact algorithm

[0042] The surface-to-surface contact algorithm is selected for anti-ballistic simulation.

[0043] 5. Define boundary conditions and apply loads

[0044] The bullet velocity direction is the normal direction of the target plate, the initial velocity of the bullet is 820m / s, a fixed target plate is defined on the boundary surface, and symmetric boundary conditions are defined to impose translational and rotational constraints on the target plate. The contact between the bullet and the target plate adopts the surface erosion (ESTS) contact algorithm.

[0045] 6. Solution

[0046] Set the analysis time output steps and submit the solution.

[0047] 7. Observe the penetration process

[0048] Post-processing software is used to solve and analyze the projectile-target model.

[0049] Example 2

[0050] 1. Selection of unit type

[0051] Both the bullet and the target plate use SOLID164 units. The SOLID164 unit is an explicit three-dimensional structural entity unit with 8 nodes. The nodes have X, Y, Z translation, velocity, and acceleration degrees of freedom.

[0052] 2. Build the model

[0053] The bullet uses the Type 53 7.62mm WO-109C armor-piercing incendiary bullet. The bullet model is simplified according to the actual size, and simplified to a cylinder with a hemispherical head.

[0054] The target plate size is 500mm×500mm and the thickness is 8mm. The initial velocity of the bullet is 825m / s. When simulating, taking 1 / 4 of the structure for modeling can greatly reduce the amount of calculation and shorten the calculation time.

[0055] 3. Grid division

[0056] The target is divided into hexahedral grids.

[0057] 4. Define the contact algorithm

[0058] The surface-to-surface contact algorithm is selected for anti-ballistic simulation.

[0059] 5. Define boundary conditions and apply loads

[0060] The bullet velocity direction is the normal direction of the target plate, the initial velocity of the bullet is 825m / s, a fixed target plate is defined on the boundary surface, and symmetric boundary conditions are defined to impose translational and rotational constraints on the target plate. The contact between the bullet and the target plate adopts the surface erosion (ESTS) contact algorithm.

[0061] 6. Solution

[0062] Set the analysis time output steps and submit the solution.

[0063] 7. Observe the penetration process

[0064] Post-processing software is used to solve and analyze the projectile-target model.

[0065] Example 3

[0066] 1. Selection of unit type

[0067] Both the bullet and the target plate use SOLID164 units. The SOLID164 unit is an explicit three-dimensional structural entity unit with 8 nodes. The nodes have X, Y, Z translation, velocity, and acceleration degrees of freedom.

[0068] 2. Build the model

[0069] The bullet uses a 53-type 7.62mm ordinary steel core bullet. The bullet model is simplified according to the actual size, and is simplified to a cylinder with a hemispherical head. The target plate size is 500mm×500mm and the thickness is 4mm. The initial velocity of the bullet is 820m / s. When simulating, taking 1 / 4 of the structure for modeling can greatly reduce the amount of calculation and shorten the calculation time.

[0070] 3. Grid division

[0071] The target is divided into hexahedral grids.

[0072] 4. Define the contact algorithm

[0073] The surface-to-surface contact algorithm is selected for anti-ballistic simulation.

[0074] 5. Define boundary conditions and apply loads

[0075] The bullet velocity direction is the normal direction of the target plate, the initial velocity of the bullet is 820m / s, a fixed target plate is defined on the boundary surface, and symmetric boundary conditions are defined to impose translational and rotational constraints on the target plate. The contact between the bullet and the target plate adopts the surface erosion (ESTS) contact algorithm.

[0076] 6. Solution

[0077] Set the analysis time output steps and submit the solution.

[0078] 7. Observe the penetration process

[0079] Post-processing software is used to solve and analyze the projectile-target model.

[0080] Table 1. Simulation results of steel plate in the implementation example

[0081] Examples Tempering temperature / ℃ Steel plate thickness / mm Crater depth / mm Back bulge / mm Example 1 180 8 9.7 1.6 Example 2 200 8 9.5 1.2 Example 3 220 8 8.9 0.9

[0082] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A projectile penetration numerical simulation method, characterized in that: It includes the selection of unit type → establishment of unit model → mesh division → definition of contact algorithm → definition of boundary conditions and application of loads → solution → observation of penetration process; it specifically includes the following steps: 1) Selection of unit type Both the bullet and the target plate are made of SOLID164 units; 2) Build a model The bullet uses the Type 53 7.62mm WO-109C armor-piercing incendiary bullet. The bullet model is simplified according to the actual size, and simplified to a cylinder with a hemispherical head. 3) Grid division The target is divided into hexahedral grids; 4) Define contact algorithm Select the surface-to-surface contact algorithm for anti-ballistic simulation; 5) Define boundary conditions and apply loads The bullet velocity direction is the normal direction of the target plate. A fixed target plate is defined on the boundary surface, and symmetric boundary conditions are defined to impose translational and rotational constraints on the target plate. The contact between the bullet and the target plate adopts the surface erosion contact algorithm; 6) Solution Set the analysis time output steps and submit the solution; 7) Observe the penetration process Post-processing software is used to solve and analyze the projectile-target model.

2. The projectile penetration numerical simulation method according to claim 1, characterized in that: In the step 1), the SOLID164 unit is an explicit three-dimensional structural entity unit with 8 nodes, and the nodes have translation, velocity and acceleration degrees of freedom in the X, Y and Z directions.

3. The projectile penetration numerical simulation method according to claim 1, characterized in that: In the step 2), the target plate has a size of 500 mm×500 mm and a thickness of 8 mm; the initial velocity of the bullet is 820-835 m / s.

4. The projectile penetration numerical simulation method according to claim 1, characterized in that: In the step 2), taking 1 / 4 of the structure for modeling during simulation can greatly reduce the amount of calculation and shorten the calculation time.

5. The projectile penetration numerical simulation method according to claim 1, characterized in that: The initial speed of the bullet is 820m / s.

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