Optimal braking of a rigid conical impactor by a layered shield at normal impact with viscous effects

In a number of previous investigations [1-3] in the field of impact-penetration interaction, the problem of determining the minimum areal density of a layered shield was considered. The influence of the different penetration conditions on the optimal structure of the layered shield was researched, in particular friction, the weakening effect of the free surfaces of the plate, geometric factors (different shapes of impactors). The previous results lead to the conclusion that in the optimal structure of the shield the layers are located in the descending order of the density. In this paper, a new formulation of the optimization problem based on the modernized empirical model by F.F. Vitman and V.A. Stepanov taking into account the viscosity effect for conical impactors is investigated. This paper shows that viscosity has a qualitative effect on the optimal shield structure versus the base formulation of the problem by [3].