圆柱形预制破片在爆炸冲击作用下的数值分析及结构优化

Numerical simulation and structural optimization of cylindrical prefabricated fragments under explosion impact

为降低一种复合型预制破片在脱离预制破片战斗部时的损伤率,基于实际某井字形圆柱形预制破片尺寸设计了十字形、米字形和同心圆复合形结构。利用LS-DYNA有限元数值模拟软件对预制破片断面结构进行了动力学分析和结构优化。结果表明:预制破片加强筋之间的外壁上发生了较大变形,距离加强筋越近的位置变形越小。增加加强筋数量和将加强筋沿冲击载荷方向排布利于提升预制破片外壳的整体刚性,井字形断面结构在非径向爆炸载荷时抗爆强度较好,同心圆复合形断面结构抗损伤性能较好且易于加工成形。综合考虑性能和重量条件,采用5片加强筋径向布置、内圆直径Φ3.6 mm、壁厚0.22 mm的同心圆复合形圆柱预制破片结构刚度较高、质量较轻且利于生产制造。

To reduce the damage rate of a composite prefabricated fragment when it is separated from the prefabricated fragment warhead, the composite structures of cross-shaped, rice-shaped and concentric circle-shaped were designed based on the size of a certain practical wells-shaped cylindrical prefabricated fragment. The dynamic analysis and structural optimization of the section structure of the prefabricated fragments were carried out by LS-DYNA finite element numerical simulation software. The results show that large deformation occurs on the outer wall between the prefabricated fragment reinforcement ribs, and the closer the position to the reinforcement ribs, the smaller the deformation. Increasing the number of stiffeners and arranging stiffeners along the direction of impact load are beneficial to improve the overall rigidity of the prefabricated fragment shell. The anti-explosion strength of the wells-shaped section structure is better under non-radial blast load, and the concentric circular composite section structure has good damage resistance and is easy to be machined. Considering both the performance and weight conditions, the concentric circle composite-shaped cylindrical prefabricated fragments with five ribs arranged radially, inner circle diameter of Φ3.6 mm and wall thickness of 0.22 mm have higher structural rigidity and lighter weight, and are conveniont for manufacturing.