DISCUSSION ON THE RESISTANCE FORCING FUNCTION OF PROJECTILES PENETRATING INTO CONCRETE TARGETS

Based on the dynamic spherical cavity expansion model, the influences of concrete target parameters, including the uniaxial compressive strength, the Young's modulus, the Poisson's ratio and the pressure hardening coefficient on the resistance forcing function are studied. It indicates that, the Young's modulus and the uniaxial compressive strength are the most influential factors while the Poisson's ratio and the pressure hardening coefficient can be ignored for the resistance forcing function. By introducing the relationship of the Young's modulus and the uniaxial compressive strength and ignoring the influences of the Poisson's ratio and the pressure hardening coefficient, resistance force formulas are proposed based on the elasto-cracked-plastic and the elasto-plastic response regions of the targets, respectively. Furthermore, the prediction model for the projectile deceleration-time history is obtained. The terminal ballistic perdictions are in resonably good agreement with the test data, and it verifies the application of the resistance force formulas, especially in the deceleration-time history prediction and the penetration depth calculation of the larger penetrator.