柱形弹超高速撞击加筋板架结构的破片群特征分析

Regarding the issue of hypervelocity impact on ship-stiffened plate structures,the research has predominantly focused on the information about residual projectile and the characteristics of target plate breaches,while there has been a lack of research on the formation and distribution of fragment cloud. In this study,the finite element-smoothed particle hydrodynamics (FE-SPH) adaptive method,incorporating the Johnson-Cook failure criteria and the maximum tensile strain failure criteria is used to simulate the formation of the fragment cloud produced by cylinder projectile impacting a stiffened plate. Simulated results indicate that the cylindrical projectile forms a fragment cloud with double-saddle shape due to the influence of stiffeners during the impact process,and the main part of the fragment cloud is concentrated at the front end, including hazardous fragments on the inside and small fragments on the outside. Moreover,the distribution of fragments is consistent with the experimental result. The impact process is divided into three stages based on the cbharacteristics of fragment distribution, and the formation and propagation of fragments at each stage are discussed. The topographic characteristics of fragment cloud under various stiffener configurations are presented by varying the impact location of cylindrical projectile. Finally, the characteristic parameters, such as mass and kinetic energy, of the hazardous fragments in the fragment cloud are studied,and the degrees of influence of different impact locations are discussed,which is used to assess the damage ability of hazardous fragments to the rear plate. The analyzed results show that the fragments concentrate towards specific areas to form double-saddle shape and saddle shape due to the influence of the stiffeners. The generation of hazardous fragments is primarily influenced by the main stiffener.