ADVANCED COMPUTATIONS FOR BALLISTIC IMPACT PROBLEMS

This article addresses some issues and solutions for ballistic impact computations. A discussion of the strengths and weaknesses of existing computational techniques is presented, and this is followed by a description of a new computational technique that is well-suited for ballistic impact computations. This new approach uses both finite elements and meshless particles. The initial grid is composed entirely of finite elements. Then as the solution progresses, the highly strained finite elements are automatically converted into meshless particles. Generally, most of the grid remains as finite elements, and this allows for an accurate and efficient solution for the less distorted portion of the problem. Only the highly distorted regions of the problem are converted into meshless particles, and these meshless particles can accurately and robustly represent the high distortions that the finite elements are not able to represent. Several examples are provided to illustrate this approach. Included is the capability to compute the formation of Behind Armor Debris (BAD) and to track it through large distances.