关键词: 超高速碰撞, 破片群, FE-SPH自适应耦合方法, 风险破片

Abstract: Based on hypervelocity impact of ship-stiffened plate structures, the previous research had predominantly focused on the information of residual projectile and characteristics of target plate breaches, while there are deficiencies in the formation and distribution of the fragment cloud. In this study, the finite element-smoothed particle hydrodynamics (FE-SPH) adaptive method, incorporating the J-C failure model and the maximum principal strain failure criterion, was used to simulate the formation of the fragment cloud produced by cylinder projectile impacting stiffened plate. Simulation results indicated that during the impact process, influenced by the stiffeners, the fragment cloud exhibited a double-saddle shape, and the main body of the fragment cloud was concentrated at the front end, including hazardous fragments on the inside and small fragments on the outside. Moreover, the distribution of fragments was consistent with the experiment. Based on the characteristics of fragment distribution, this paper divided the impact process into three stages, and discussed the formation and propagation of fragments at each stage. Furthermore, the characteristics of fragment cloud under various stiffener configurations were presented, by varying the impact location of the cylindrical projectile. Finally, the hazardous fragments within the fragment cloud were identified, the mass and kinetic energy were provided, and the influence of different impact locations was discussed, which was used to assess the damage ability of the hazardous fragments to the rear plate. The study results show that, Fragments were concentrated towards specific areas, then exhibited double-saddle shape and saddle shape, with the influence of the stiffeners. Moreover, the generation of hazardous fragments was primarily influenced by the main stiffener.

Key words: hypervelocity impact, fragment cloud, FE-SPH adaptive method, hazardous fragment