The Research On Critical Shock Initiation Phenomenon For Heterogeneous Condensed Explosives

In the detonation field, the shock initiation phenomenon (SIP) for heterogeneous condensed explosives (HCE) is a leading research subject. It has a great effect on the military science, industrial development and engineering application and so on. Large amounts of documents put their attentions on the SIP. Yet most of them just surveyed the shock sensitivity gap thickness for different explosives, and little studied the SIP near the critical initiation pressure point (CIPP). In addition, mechanics for SIP is very complex, and the shock initiation course would vary with the small differences of initial or boundary conditions, which could lead to two completely different results: steady-state detonation and extinction. In recent years, Most of papers focused on the process of shock to steady-state detonation transition (SSSDT) together with its numerical simulation. And few were on the critical extinction, even none of them was on numerical simulation for a critical extinction process. For the reasons above, the paper contains the following contents:1. Studying the SIP near the CIPP.2. Studying the process of shock to extinction transition (SET) near the CIPP and its numerical stimulation.Three fundamental features were found in detonation of explosives: high speed, high temperature and high pressure. Thus the research should be based on experiments.In this thesis, three kinds of HCE are investigated based on the experiments, numerical calculation and simulation. Some innovative conclusions are drawn as follows:1. Two-dimensional experiment system was established for SIP. The critical gap thickness value and threshold pressure are measured for three kinds of HCE.2. Manganin-constantan compound Lagrange gauge is originally used in two- dimensional axisymmetric experiment, which paves a wide road for popularization of two-dimensional experiment.3. Two-dimensional Lagrange analysis method is firstly used to treat experimental data. Radial expansion is considered in calculation equations, and calculation solutions accord with experiment course well.4. Corresponding conclusions are drawn from numerical calculation and simulation.5. It can be seen from the experiment/calculation/simulation that current chemical reaction rate equation could only describe SSSDT that is under the condition of positive feedback, while it failed to describe SET near the CIPP. For this purpose,...