Research on Tensile Mechanical Properties and Damage Mechanism of Composite Solid Propellants

The study focuses on the tensile mechanical properties and damage mechanisms of composite solid propellants under extensive temperatures and strain rates. Uniaxial tensile tests of the propellant have been conducted at the temperature of +70 °C, +23 °C and −50 °C separately with strain rate changing from 0.05 %/s to 150 %/s. According to the differences of tensile mechanical properties under those three classic temperatures, the damage mechanism of composite solid propellants are investigated by numerical simulation using particle packing models under varying strain rates and temperatures. The results show that the quantity of damaged interfaces between particles and binder as well as damage evolvement extents under loading are strain rate dependent. With the rising of loading strain rates, the quantity of the damaged interfaces increases while the development of particle dewetting damage and the damage accumulation process are postponed. Especially under lower temperature, the “bifid hump” is more obvious for composite solid propellant because of binder damage dominant. The typical stress‐strain curves under different strain rates are provided finally.