Calculation of multistep thermal decomposition of HMX- and TATB-based composite explosive for fast cook-off

In order to investigate the thermal response of explosive at fast cook-off environment, the fast cook-off tests of HMX-and TATB-based composite explosives, subjected to external fire scenario, were carried out. The ignition time of explosive was measured. A model of explosive fast cook-off test was set up. The thermal decomposition of each constituent was described by the multistep chemical kinetics model. A multicomponent grid unit calculation method was put forward. The thermal decomposition of HMX-and TATB-based composite explosives for fast cook-off was calculated. Ignition time, ignition position and temperature distribution in explosive were analyzed. The error between the measured and calculated ignition times of explosive is below 5%. The effects of different constituent ratios of composite explosive on its thermal reaction performance were analyzed. The ignition time and temperature of explosive are changed little as the HMX and TATB contents are changed.