Study on the change of gas generation law caused by fracture of propellant charge
The harsh launch environment will cause stress and fracture of propellant charge in the projectile base. If the fracture is serious, it may lead to unsafe launch of the gun. It is one of the important keys and the most difficulties to accurately simulate the gas generation law of fracture propellant charge in the launch safety. In this paper, a dynamic stress and fracture simulation software of propellant charge is established based on the discrete element method, with which the dynamics process of stress and fracture of propellant charge is numerically performed. The corresponding experiments are carried out. According to the computed results of stress and fracture, the new combustion functions are created, and the numerical simulation of the fracture propellant charge combustion in closed bomb is implemented. The numerical simulation results are promising and in good agreement with the closed bomb tests, which indicates that the new combustion functions are effective against simulating the change of gas generation law caused by fracture of propellant charge. Achievements of the present results are precise prediction of the fracture degree of the propellant charge under different loading stress, which reduce the test costs, and provide the theoretical basis of the evaluation technology of the launch safety of propellant charge.
Keywords: Combustion function, discrete element method, fracture propellant, gas generation law, stress and fracture