High Strain Rate Effect on Tensile and Compressive Property of Carbon Fiber Reinforced Composites

With high strength and stiffness-to-weight ratios, Carbon-Fiber-Reinforced Polymer (CFRP) composite has been applied to the separation device of the rocket by shaped charge jet. But dynamic tensile and compressive properties of CFRP under high rate strain are still unclear. In the article, tensile testing along transverse direction are conducted. The quasi-static tests (10-3 s-1) use a universal testing machine and high dynamic loadings of 800 s-1 and 1600 s-1 tests adopt a high-speed tensile testing machine. Meanwhile, dynamic compressive tests of unidirectional and cross-ply laminated specimen under the thickness direction loading are implemented by a Split Hopkinson Pressure Bar (SHPB) from dynamic loading 500 s-1 to 2500 s-1. Test results show that compared with static tests data, both transverse tensile modulus and strength of CFRP composites materials at dynamic loadings are sensitive to tensile tests. The compressive peak stress and stiffness of specimens also have an increasing tendency with the increases of the strain rate. Furthermore, for failure mode of tensile specimens, the crack propagation of the specimen fracture is along the interface of the fiber/matrix under all loading conditions. The failure modes of compressive specimens are different as the strain rate changes. The higher the strain rate, the more severe the crushing.