冲击波载荷下含裂纹复合固体推进剂动态响应及损伤演化

Solid propellants with crack defects are susceptible to crack propagation under shock wave loading during their service life,significantly affecting their structural integrity. The dynamic mechanical response and defect-induced damage evolution of hydroxyl-terminated polybutadiene (HTPB) propellants under varying shock wave intensities are investigated using a shock tube apparatus, and the schlieren imaging and 3D digital image correlation (3D-DIC) techniques. Shock wave loading experiments are conducted on both defect-free and crack-defected propellant specimens within a pressure range of 0. 3 to 0. 9 MPa, and the dynamic deformation and damage evolution processes of propellant specimens are captured in the experiments. The results indicate that the deformation of the defect-free specimen exhibits a parabolic profile,and The deformation of the sample increases with the increase in impact pressure. The specimens with different crack depths show different degrees of crack growth under 0. 9 MPa impact pressure,and the multiple impacts will result in superimposed damage. The critical failure crack depth ratio is 50% -75%. Residual specimen analysis reveales that the matrix cracking,particle debonding,and particle fracture are the primary failure mechanisms. These findings provide valuable insights for assessing the structural integrity of solid rocket motors under ignition shock condition.