Penetration Damage Effects of Corundum Rubble–Concrete Target Based on Random Inhomogeneity Modeling Method

The random inhomogeneity of rubble stone–concrete targets is the fundamental cause of the significant randomness in anti-penetration performance, thereby limiting the engineering application of rubble stone–concrete. Here, to study the penetration damage effects and the anti-penetration mechanisms of the rubble stone–concrete, a random inhomogeneity modeling method is proposed, which constructs high-fidelity hexahedral mesh models of rubble stone–concrete targets. The reliability of the numerical simulation methodology and parameters is validated by comparison with penetration test data. The effects of corundum rubble size, corundum rubble volumetric percentage, concrete strength, and projectile impact velocity on penetration damage and penetration depth are discussed. The results reveal that the optimal corundum rubble size should equal 1.0 times the projectile diameter to balance the performance and stability of anti-penetration at the 30% volumetric percentage. As the concrete strength increases, corundum rubble gains more support during the penetration process, which also makes significant contributions to improving anti-penetration performance. The percentages of the penetration resistance impulse contribution from concrete and corundum rubble are unrelated to the projectile impact velocity. Moreover, an empirical formula for predicting penetration depth in corundum rubble–concrete targets is proposed, which provides a reference for evaluating the anti-penetration performance of corundum rubble–concrete.