冲击波和高速破片对固支方板的联合作用数值模拟

Numerical simulation of steel plates subjected to the impact of both impact waves and fragments

为探讨固支方板结构在爆炸冲击波和高速破片联合作用下的变形破坏特点及规律,利用有限元分析软件ANSYS/LS-DYNA开展冲击波和高速破片对固支方板的联合作用数值模拟计算,阐述装药驱动预制破片的运动过程,分析冲击波载荷和破片载荷以及钢板在联合载荷作用下的变形破坏模式,并与试验进行对比。结果表明,数值计算结果与试验结果较为吻合;炸药底部中心处预制破片的初速最高,边缘处最低;在试验工况下,冲击波先于破片作用于结构,破片群总动能远大于爆轰产物及冲击波传递给结构的动能,破片群是造成钢板中心出现冲塞破口的主要因素,应作为防护结构的主要设计载荷。

The main objective of this study is to explore the deformation feature and damage pattern of a steel plate under the synergetic effects of blast and fragments loading. The combined blast and fragments loading effects under the condition of cast TNT and prefabricated fragments acting on a steel plate, are simulated using the finite element program ANSYS/LS -DYNA. The flight of fragments driven by the charge is predicted, and the blast loading and fragments loading are analyzed respectively, while the deformation and damage characteristic under the combined loading are compared with experiment results. The simulation results agree relatively well with the experimental results. Meanwhile, it is seen that the fragment at the center of the charge bottom has the highest velocity and the lowest velocity occurs at the edge. Under the experimental condition, blast reaches the structure first and fragments impact subsequently, and the total kinetic energy of fragments is much larger than that of blast wave and explosion products transmitted to the structure. The punched hole appearing in the central region of the steel plate is mainly caused by the dense fragment cluster, which should be treated as the main target load for protective structures.