Dynamic cavity-expansion penetration model of elastic-cracked-crushed response for reinforced-concrete targets

Herein, an improved dynamic cavity-expansion model for penetration of reinforced-concrete targets is proposed. The circumferential restriction effect derived from reinforcing bars in both the cracked and crushed regions has been considered in the proposed model, and the theoretical solutions for the cavity radial stress in compressible and incompressible reinforced concrete are obtained. Through the analysis of concrete strength and reinforcement ratio, we establish a simplified formula to calculate the penetration resistance of reinforced-concrete targets. Moreover, the calculation method of a direct impact resistance for the projectile on the reinforcing bars is developed, and thus, the engineering model for penetration of reinforced-concrete target is constructed. By comparing with the experimental data and empirical formula, the validity of this new model is further verified.