Effects of Specimen Size and Boundary Conditions on the Penetration Depth of Metal Ceramic Structure

Ceramics has high hardness but low density and has been used in defense to enhance the protection of human bodies or vehicles against projectile penetration. Ceramics can defeat a ballistic threat by deforming and fracturing a metal projectile, thus eliminate or reduce the depth of penetration in backing steel. This study investigates the penetration progress of a tungsten alloy projectile into an Al2O3 ceramics (alumina) backed with high strength steel 4340. Depth of penetration tests were conducted on ceramics/steel specimens by WNiFe projectiles at impact speeds around 1280m/s. Numerical simulations corresponding to the test configurations were carried out using commercial software (Autodyn) and the prediction of crater profile coincides with experimental results. Further simulations investigated the effects of specimen size and boundary conditions on the total depth of penetration; the performance of metal ceramic structure against ballistic penetration was explored and evaluated.