Numerical analysis on impact safety of fuel air explosive

Fuel air explosive (FAE), different from high energy explosive is a three-phase medium consisting of metal solid particles, water and gas. Its mechanical behavior is affected by initial condition and loading condition. In this paper a three-phase material model for FAE explosive subjected to shock loading was presented. In the model the FAE explosive was modeled as a three-phase mixture which contains solid metal particles, water and gas. The solid metal particles formed a skeleton structure. The liquid and gas were filled in the void of the skeleton structure. In addition, the gas adiabatic compression model was introduced. The profiles of stress and temperature of individual phases could be showed in the material model. Hence it could be a way to reasonably validate the safety of fuel. This material model was embedded into dynamic software AUTODYN as user subroutines. Finally, the model was applied to analyze the response of the FAE charge when the FAE warhead was dropped from 20m high down to steel plate vertically. Based on the stress status and temperature distribution in the charge, the safety of FAE charge was discussed.