RADIAL EXPANSION OF CAVITIES PRODUCED BY THE AXISYMMETRIC STEADY PENETRATION OF HYPERVELOCITY RODS (IMPACT, PLASTICITY).

摘要

A model for the expansion of a cavity created during the penetration of high speed rods is presented. This model was formulated by making several assumptions as to the behavior of the deforming target material during the cavity expansion process. The assumptions are supported by previous experimental and finite difference investigations. Upon specification of the matching conditions at the boundaries of the plastic deformation regions, the governing system of non-linear field equations reduces to simpler ordinary differential equations. Initial conditions are estimated and the resulting initial value problems are solved with a standard Runge-Kutta technique. Parametric trends are subsequently established and the model predictions compare quantitatively well with experimental observations. It is concluded that the model accurately predicts the proper behavior but the accuracy of results depends significantly upon the precision with which the initial conditions and the target material characteristics may be specified.