Steady State Penetration of Compressible Rigid Perfectly Plastic Targets

Steady state axisymmetric deformations of a homogeneous, isotropic, compressible and rigid perfectly plastic target being penetrated by a rigid cylindrical penetrator with a hemispherical nose are studied by the finite element method. The steady state is reached with respect to an observer situated on the penetrator nose and moving with it. Tillotson’s equation, restricted to mechanical deformations, is used to express the pressure as a function of the mass density. Contact between the penetrator and the target is assumed to be smooth. The effect of compressibility of the material is delineated by comparing results for compressible and incompressible materials. Also studied is the effect of the penetrator speed on target deformations.