Research on the Nonlinear Dynamic Theoretical Modeling and Response Characteristics of a Projectile–Fuze System Penetrating a Finite-Thickness Concrete Target

The dynamic behavior of projectile–fuze systems under high-velocity penetration is extremely complex, which causes great challenges in fuze performance evaluation and design. Existing research mainly relies on numerical simulation, while the corresponding theoretical studies are very limited. To overcome the limitations in current theoretical studies and provide a reliable reference model, this paper develops a nonlinear dynamic model for projectile–fuze systems penetrating finite-thickness concrete targets. The model adopts a hierarchical modeling strategy and comprehensively considers the projectile–target interaction, projectile–charge coupling effect, fuze system and projectile–fuze coupling. Based on the three-stage projectile–target penetration mechanism (cratering, tunneling, shear plugging), finite element (FE) dynamic theory, and the multi-degree-of-freedom (MDOF) lumped parameter approach, an integrated dynamic theoretical framework is established. On this basis, the influences of striking velocity, thickness and compressive strength of concrete target, and friction between the projectile and target on the dynamic characteristics of the projectile–fuze system are analyzed. The results suggest that in the process of penetration, the fuze overload response shows severe oscillations, which are mainly concentrated in the cratering stage and the early stage of tunneling. In this period, the striking velocity, target strength and friction have a significant impact on the overload response. Penetration velocity and resistance are highly dependent on the striking velocity, target strength, target thickness and the friction between the projectile and the target, and these factors affect the fuze overload response by influencing the penetration resistance and the projectile–target interaction time. The theoretical modeling method of the penetrating projectile–fuze system can serve as a guidance in related fields.