I am using sol701/601 for drop and crash testing, but I am having some doubts about the material model. I am using a nonlinear-plastic material model with a stress strain curve I got from a tensile test. The material is POM, it is a polymer, I wouldnt say it is brittle, but it is not as flexible as lets say HDPE. When trying to interpert results of a drop test (or any other nonlinear analysis) I usually look at the strain and von mises stress results and the basic concept is the amount of plastic zones and how much did they went into the plastic zone. But this makes it very hard to predict exactly where the fracture will start. Is there a better material model / guidelines to determine fracture in such "semi" brittle material?