A Study On The Influencing Factors And Criterion Of Fragment Strike Warhead

Insensitive munitions is a relative new term, and which will not react violently in an accident situation. The background of the research in this paper is insensitive munitions technology, the response and regular pattern, as well as the initiation criterion, of the warhead to fragments impacting are the main research content.In this dissertation, based on the assumptions of one-dimensional plane shock, impact dynamics and explosive "hot spot" initiation theory, the detonating mechanism of warhead impacted by fragments was analyzed and then warhead was simplified to explosive coverd with shell. Then, numerical simulation and theoretical calculations were carried to research on the process of warhead detonation by the software Autodyn. After then, the changes of explosive thichness and dimeter and length of fragments, shell thickness and the impacting angle were applied to analyze the laws of explosive initiation behavior, and the effect of different factors on the initiation process was explored. Based on the rod criterion by James H.R and one-dimensional initiation criterion by Walker and Wasley, Critical energy criterion contained with the length, diameter of the fragment and the thickness of the shell was deduced by theoretical derivation, and the existing experimental data was used to amend the criterion. In adidation, several grades including detonation deflagation combustion and mechanical shock were divided to describe the extent of reaction. Typical experiments of fragments impacting explosive covered with shell were chosen to substitute into the critical energy criterion, and critical energy coefficients wrre obtained from it. Then the critical energy criterion of explosive covered with shell detonated by fragments impacting in different grades was deduced.