Effect of dynamic plastic deformation on the normal penetration of metallic plates

The present study is an attempt to develop an engineering model to predict the response of thin and intermediate thick metallic plates impacted normally by rigid, blunt cylindrical projectiles at subordnance impact speeds (100-300 m/s).; The analysis considers the dynamic plastic plate deformation in conjunction with the plugging process as a failure mode for penetration. Liss' penetration model (1982, 1983) is used to describe the behavior of the target material in the impact zone (the area under the projectile), and a dynamic plastic bending model, including the effect of transverse shear, is used to describe the global response of the target plate. The effect of transverse shear is taken into account in the yield criterion of the plate material as well as in the dynamic equilibrium equations. A rate-independent, rigid-perfectly plastic material is assumed in conjunction with a linearized form of the von Mises yield criterion in three dimensions.; The penetration model is coded in a computer program where the interaction between the local plugging model and the global target deformation is analyzed.; A number of ballistic tests were conducted to examine the response of the target plates to impact loadings including perforation. A compressed-gas gun was designed, built and used to launch steel projectiles against 6.4 mm thick aluminum plates at impact speeds of 100 to 300 m/s.; Analytical and experimental results showed good agreement for the final deformation of the target plate and for the projectile residual speed after perforation. Comparison with previous models showed an improvement in the prediction of the total deformation of the target plates.