Numerical simulation on initiation of charge under combined action of shock wave and fragment impact

To study the initiation characteristics of charge subjected to the combined action of shock wave and fragment impact, the initiation reaction of the undamaged explosive was numerically simulated by the three-term ignition-and-growth reaction rate model. The critical impact velocity range from 497 to 500 m/s was obtained for the initiation reaction of the undamaged explosive. And it is in agreement with the experimental result. The initiation reaction of the pre-damaged explosive was numerically simulated by changing the coefficient G₁ in the three-term ignition-and-growth reaction rate model. The coefficient G₁ in the model can reflect that the particle size change of the shock-damaged explosives affect the sensitivity of the explosives.