ALUMINUM PLATE PERFORATION: A COMPARATIVE CASE STUDY USING LAGRANGE with EROSION, MULTI-MATERIAL ALE, and SMOOTH PARTICLE HYDRODYNAMICS

The focus of the present work is to perform an assessment of a relatively new class of numerical methods, referred to as meshfree methods, that offer analysts an alternate analytical technique for simulating this class of ballistic problems, without a priori trajectory knowledge, nor resorting to ad hoc criteria. The assessment is made by the comparison of projectile residual speeds provided by the various techniques, when used to simulate a ballistic impact experiment. The techniques compared are the meshfree method known as Smooth Particle Hydrodynamics, a Multi-Material Arbitrary Lagrange Eulerian (MM-ALE) technique, and Lagrangian with material erosion. Such comparisons inherently have aspects of an apples-to-oranges-to-pears comparison, but an effort has been made to minimize the numerous ancillary aspects of the different simulations and focus on the capability of the techniques. To minimize unintended differences in the simulations, the following three key aspects remain constant: 1. Only one software package (code) is used, 2. The same constitutive model is used, 3. The models were constructed by one analyst with a similar level of experience using the three modeling techniques. Even with these considerable constraints on the simulation comparisons, it is obvious that the results are subject to the analyst’s knowledge and skills in applying the various analysis techniques to the impact simulation. Thus the reader should not assess the merits of these techniques on the provided ‘answers,’ but should instead focus on the relative merits of each technique and their applicability to simulations of interest.