Investigation of the In-Bore Structural Integrity of a Kinetic Energy Projectile

Abstract

In-bore failure of a large caliber tungsten heavy alloy long rod penetrator has been studied. A 2D axisymmetric finite element analysis has been carried out to check its in-bore structural integrity. The objective of structural analysis has been to obtain accurate stress field in the penetrator. Three phase approach was adopted to analyze the problem. The analysis involved quasi static analysis of the entire penetrator and fracture mechanics approach. A high stress concentration with steep spatial gradient has been found in the fillet region of rear thread/groove of the penetrator. Although, stresses are very high at the fillet of the rear groove, they reduce to safe limit rapidly. Though bulk failures are not predicted, high axial stresses at thread roots can cause catastrophic failure when cracks are present. Fracture mechanics based approach has been used to find the desired fracture toughness for a given crack size.