Abstract:
Aiming at the complex multi-physics coupling process involving penetration and explosion in sequential strikes by multiple projectiles, there is currently a lack of corresponding theoretical prediction methods. To address this, this paper proposes a theoretical model based on a decoupling-modeling approach for predicting the entire process of multiple projectiles sequentially penetrating and exploding in concrete targets. The model separately describes the penetration and explosion stages: the penetration process employs dynamic cavity‑expansion theory to construct a resistance function, takes into account the influence of projectile inclination and prior damage, and solves the projectile trajectory by explicit finite‑difference integration of the equations of motion; crater morphology is estimated using empirical formulas, with the resulting crater morphology serving as the initial condition for the next strike, thereby enabling rapid prediction of cumulative damage throughout the sequential penetration‑explosion process. Furthermore, full‑process numerical simulations of a three‑projectile sequence were conducted to validate the theoretical predictions under several typical firing configurations. The results demonstrate that the theoretical model can accurately predict the sequential penetration depth. Although deviations in crater morphology exist for the first penetration-explosion event, the prediction accuracy improves significantly as the projectile sequence advances. The penetration depth of subsequent projectiles is notably enhanced due to concrete pre‑damage, with the greatest gain occurring inside the crater tunnel zone—yet being highly sensitive to impact‑point location—while inside the funnel zone the gain decays gradually with increasing inter‑projectile spacing. The proposed theoretical model is computationally efficient and can serve as a theoretical prediction tool for damage assessment in multi‑projectile sequential strikes.