Predicting and modeling material failure under impact loading

摘要

A method for predicting and modeling material failure in solids subjected to impact loading is outlined. The method uses classical void growth models of Gurson and Tvergaard in a material point method (MPM). Because of material softening, material stability is lost. At this point, the character of the governing partial differential equations changes, and localization occurs. This localization results in mesh dependence for many problems of interest. For many problems, predicting the occurrence of material failure and its extent is necessary. To enable this modeling, it is proposed that a discontinuity be introduced into the displacement field. By including a dissipation-based force- displacement relationship, the mesh dependence of energy dissipation can be avoided. Additionally, the material point method provides a means of allowing large deformations without mesh distortion or introduction of error through remapping.