Use of Coupled Smooth-Particle Hydrodynamics/Lagrangian Method in the Simulation of Deformable Projectile Penetration

Abstract

Mesh-dependent finite element (FE) analysis poses considerable limitations in terms of applying it in large deformation problems. As simulations such as projectile penetration are largely dependent on the material failure criterion, the artificial element erosion technique, which is usually incorporated in mesh-dependent FE techniques, may result in considerable inaccuracies. Therefore, over the last few decades, computational mechanists and engineers have focussed on implementing a mesh-independent analysis method to overcome the numerical instabilities that occur in mesh-dependent FE methods. The smooth-particle hydrodynamics (SPH) technique is one of the methods that is becoming popular among computational mechanists and engineers. The knowledge and understanding of different parameters involved in such simulation is essential prior to its application. In this study, a comprehensive numerical investigation of projectile penetration through monolithic aluminium plates using the SPH technique has been performed. While there have been studies reported in published literatures on the application of the SPH technique on projectile simulations, very limited attention has been placed on investigating the influence of different parameters on the analysis results, especially on deformation of the projectiles. One of the main objectives of this study is to investigate the contribution of different numerical parameters on the simulation of complete penetration of deformable projectiles (5.56 mm x 45 mm NATO standard) through 16 mm AA5061-H116 aluminium plates. The effects of particle density, smooth length, different particle sorting options, and scale factor for smooth length, have been parametrically studied and presented. In addition, the penetration mechanism of projectiles through a metallic target has been numerically and experimentally studied. Numerical simulations show very good agreement with the experimental results. The velocity time histories for monolithic aluminium plates show a “dip” in its velocity reduction, which is considerably difficult to observe in mesh-dependent methods. Three stages of the penetration process have been numerically identified and discussed.