Numerical simulation of expansion and rupture of variable wall thickness tube under internal explosion loading

The wall thickness of blast fragmentation warhead was generally designed to be constant in the past. The wall thickness of current high velocity kinetic energy blast fragmentation warhead is designed to be variable. The dynamic simulation software AUTODYN with the stochastic destruction model based on Mott fragment distribution theory is used to study the physical processes of expansion and rupture of variable wall thickness tube under internal explosion loading. The results show that the tube surface particle velocities at different positions are in good agreement with the experimental results in the situation of initiation at small end. In the specific case of the tube structure and the charge, the initiation mode has significant effect on the segment number of the circumferential direction at different axial positions. For variable wall thickness tube, the quality of fragmentation can be improved by using the high energy explosives and the initiation from the big end.