Transverse loading and response of long rod penetrators during high velocity plate perforation

Summary This paper describes the development of mechanically coupled engineering models to predict transverse loading and response of long rod penetrators associated with high velocity perforation of thin to moderately thick plates. Test results for L/D = 20 tungsten alloy rods are presented to illustrate the distinct effects of impact yaw and obliquity on terminal ballistic transverse loading and response of rod penetrators. The yaw effects loading model considers the plate cutting contact force that travels down the side of the rod when yaw is sufficient for contact with the edge of the breaching hole. The obliquity effects model addresses transverse loading due to asymmetric pressure relief as the rod approaches the rear surface and exits the plate. In both cases, the loading is presumed to be impulsive and three-dimensional vector relationships are used to account for the complex encounter geometries associated with arbitrary combinations of impact yaw and obliquity. The response model includes predictions of rod deformation and fracture and post-perforation linear and angular velocity vectors of the residual rod. Model predictions are compared with test results for titanium and tungsten alloy rods.