Numerical Simulation of Mechanical Characteristics of a Gas Generator Grain under Temperature Load

Abstract

In view of the crack phenomenon in the low temperature storage process of a certain type of gas generator, the viscoelastic finite element method is used to study a certain type of adherent cast solid gas generator grain, and the numerical simulation study is completed. The simulation results show that the stress concentration on the inner surface of the star shaped grain is located at the B point of the arc of the star root during the process of cooling and low temperature. At the initial moment of curing stage the rising trend of stress and strain of B point is not obvious, before the end of cooling stage the linear increases with the increase of time. During the low temperature storage, the stress relaxation and creep behavior are not obvious. The maximum stress of the B point is 0.289MPa, and the maximum strain value is 16.881%. The simulation process assumes that more simplification is made, and the actual maximum strain value may have more than 20%, which may lead to the crack phenomenon. It lays a foundation for the optimization of the propellant formula and the structure of the grain.