Failure pressure estimations on a solid propellant rocket motor with a circular perforated grain

摘要

This paper presents analytical as well as finite element estimations of the failure pressure of a typical rocket motor, which is modelled as a body of a HTPB-based propellant material enclosed by a thin-walled flexible casing of 15CDV6 steel. The estimations are based on nonlinear analyses, using stress-strain curves generated from the uniaxial tension specimens of the propellant as well as casing materials. Solid propellant being viscoelastic in nature, stress-strain curves generated at different strain rates have been used in the analysis. It is noted that the failure pressure of the rocket motor slightly increases in the presence of propellants. As the grain web thickness decreases, due to propellant burning the failure pressure slightly reduces and approaches the value of the maximum pressure in the hydroburst test of the motor case at the end of the propellant burning.