Optimization methods are increasingly used to design structures. Structural optimization with linear static analysis is pretty much mature in methodology and therefore several codes now have optimization capability for linear analysis. This is in contrast to optimization with crash and impact responses encountered in automotive, defense, transportation safety and other fields. Impact responses do not present simplicities as with linear static responses. They are highly nonlinear and noisy (i.e. non smooth) preventing the use of conventional optimization methods based on gradients or...