Topology optimization in crashworthiness design

Topology optimization has developed rapidly, primarily with application on linear elastic structures subjected to static loadcases. In its basic form an approximated optimization problem is formulated using analytical or semi-analytical methods in order to perform the sensitivity analysis. When an explicit finite element method is used to solve contact-impact problems, the sensitivities cannot easily be found. Therefore, an alternative formulation for topology optimization is investigated in this work. The fundamental approach is to change the element thicknesses based on the internal energy density distribution in the structure. Within this formulation it is possible to treat nonlinear effects, e.g. contact-impact and plasticity.