A mesoscopic numerical analysis for combustion reaction of multi-component PBX explosives

Abstract

A mesoscopic combustion reaction model of multi-component PBX explosives by using a coupled thermo-mechanical constitutive model is studied. Thereinto, based on the heat balance equation, the present temperature can be calculated; the changing physical state of different materials is described by establishing different equations of state, and based on specially appointed constitutive equations, the microcracks in PBXs are described. Furthermore, the concept of combustion reaction degree is established, which takes temperature as a criterion for changing physical state. The model is implemented within the framework of the material point method so that the different gradient in the governing differential equations could be discretized in a single computational domain and that continuous remeshing is not required with increasing reaction time. The proposed model-based simulation procedure is verified with the burn rate, the peak pressure, and temperature of PBX explosives under macroscopic scale.