Analysis Of Mechanical Response Of Solid Rocket Motor Under High Overload

As the key part of rocket, the propellant is the power source. Propellant is typical viscoelastic material and its behavior with temperature load depends on time and temperature. After the effect of temperature load, the mechanics, dimensions and structures of propellant have changed a lot which may cause bad results. At the same time, the work condition of the rocket is very rigorous for the acceleration of over 10000g while it is launched with gun. In order to keep the integrity of propellant, we need to research the stress and strain under every kind of loads, especially the viscoelastic responds with high overload at launching.Universal material test machine and Split Hopkinson Bar are used to research the compressive behavior of double-base propellant at different temperature as well as strain rate. The relations between tress and train have been got at low and high strain rate. After that, the responding laws of double-base propellant with temperature and compress ratio are analyzed.On the bases of experimental study, the nonlinear viscoelastic constitute model of Zhu-Wang-Tang was introduced in this paper, and the material parameters had been got. The validation of model parameter reveal that the constitute model of Zhu-Wang-Tang can preferably depict the relation of stress and strain.Based on the high strain rate mechanical characteristic of double base propellant, using finite element simulation software, the ZWT constitutive equations were introduced into the double base propellant material model. To a gun launched rocket, simulations and analyzing of mechanical responding were done during launching and at ignition under low temperature.These researches are useful to structure design and integrity analysis of gun launched rockets.