Numerical Simulation Of Protective Structure Resist Long Tungsten Alloy Rod Penetration

In this paper,the way of embedded cohesive element in the finite element model was used to study the protective structure resistance of tungsten alloy rod penetration.The damage of the target under different penetration patterns was discussed.The crack propagation on the ceramic target was simulated,and the bending fracture of long rod projectile after the penetration to the tilted thick metal target was studied.The anti-penetration capacity of the protective structure is discussed by studying the damage of the target plate and the long rod.The research was carried out on the ABAQUS software calculation platform.The main method adopted was to embed cohesive elements in the finite element model in batches and established a reasonable cohesive model to reflect the real material properties.In this paper,the constitutive relationship of the cohesive model was analyzed in details.Due to the limitation of using cohesive model,the finite element model was simplified in this paper,and the plane strain problem was established in the three-dimensional modeling by restricting the freedom of thickness direction.In the study of the ceramic metal composite target anti-tungsten alloy long rod projectile penetration,after embedding cohesive element in the ceramic target,the initiation,propagation and expansion of crack in the ceramic target could be simulated until the entire target plate loses its resistance.In the simulation results,the fractured zone and large crack zone could be clearly observed after the ceramic target was impacted.And the cracks at the interface between the ceramic and the metal back plate due to the action of the tensile wave was generated.The shear failure and tensile failure could be distinguished by the output of damage mode.Study on the ceramic metal composite target under different penetration patterns,and it could be seen that when long rod projectiles of different shapes penetrate the target plate,the ceramic breakage was different.According to the kinetic energy loss of long rod projectiles,the ceramic metal composite target had a weak resistance to the penetration of long rod projectiles with conical heads.In the finite element simulation of tungsten alloy long rod projectile penetrating the inclined metal target,this paper focused on the shape of long bar projectile after penetrating the target.Inthe simulation of long rod projectile with thread embedded cohesive element,it can be observed that the long rod projectile with thread will appear bending fracture phenomenon when penetrating the inclined metal target,which was basically consistent with the bending phenomenon of projectile observed in the experiment and similar to the failure morphology of projectile body recovered after the experiment.In the long rod penetration condition with large length and diameter,the impact of the thread on the long rod penetration cannot be ignored.The penetration ability of long rod projectile decreased obviously after bending and deflecting.In this paper,by simulating the penetration of long rod projectile into the multi-layer metal target protection structure,the appropriate flight space and the thickness of the metal target in front were obtained.The results could provide a basis for the design of the protection structure.