Dewetting Stress of Solid Propellant under Tensile Loading

To more effectively investigate the microscopic damage of solid propellants under tensile loading, the mathematical expression of the critical dewetting stress for the propellant was developed based on the properties of the components in the propellant and the elastic and viscoelastic theories. The results reveal that the critical dewetting stress increases with increasing the particle-matrix interface fracture surface energy, or decreasing the radius of the filled solid particles. In other words, it is more difficult for the particle-matrix interface to fail as the critical dewetting stress increases. Finally, the conclusions obtained from the developed expression are consistent with the typical uniaxial tensile test results of hydroxyl-terminated poly butadiene (HTPB) propellant, which indicates that the developed expression of the critical dewetting stress is valid. Furthermore, the test results also indicate that the effects of loading temperature and strain rate on the dewetting are mainly due to the variations of the parameter in the critical dewetting stress with different loading conditions.