Application of concrete damage evolution equation considering confining pressure and strain rate effects in projectile penetration

Repeated loading and unloading tests were carried out on concrete under different confining pressures and strain rates to characterize the damage using the decrease in elastic modulus, and a damage evolution equation considering the effects of confining pressure and strain rate was established. At the same time, the yield criterion and equation of state of the Holmquist–Johnson–Cook (HJC) model were modified by combining the experimental data of high confining pressure. The modified model was validated by performing single-element numerical simulations for different stress states. Then, experiments were carried out on the penetration of tungsten alloy projectiles into concrete slabs, with penetration velocities ranging from 172 m/s to 302 m/s. The depth of penetration and crater area were obtained. Numerical simulations were subsequently carried out using the proposed model. The results showed that this model can describe the behaviour of concrete under dynamic loading. Finally, the damage evolution mechanism of concrete during the penetration process is analysed in conjunction with the proposed damage evolution equation.