A Fluid–Solid Coupled Calculation Method of Shock-to-Detonation Transition in High Explosives

The shock-to-detonation transition (SDT) may occur in the entire explosive lifecycle, including production, storage, transportation, and usage. Shock sensitivity is one of the main indicators for safety evaluation and initiation reliability. Due to the complexity and transience of the SDT, the existing test, measurement, and device cannot fully meet the research needs, and numerical simulation is still a powerful tool. The SDT in explosives is characterized by high strain rates and large deformation. In pure reactive flow dynamic calculations, the confined tube is considered rigid. Actually, the tube strength is limited, and its mechanical response inevitably affects the reaction and flow inside. Considering the computing termination caused by mesh distortion in Lagrange methods, an Euler method for fluid–solid coupled dynamics is developed. This theory involves reactive flow dynamics, elastic–plastic mechanics, and interface tracking technology. The conservation element and solution element (CE/SE) method is applied to solve governing equations, and the calculated state parameters at the von Neumann spike agree well with theoretical values. Then the mechanical response of the tube and the expansion of reaction products are analyzed in depth. Overall, this work provides an approach to gain better insight into the SDT of actual explosive charge.