Impact compression performance of three-dimensional five directional glass fiber/epoxy resin braided composite circular tubes in low-temperature environment

Three-dimensional and five-directional (3D5D) glass fiber/epoxy resin braided composite circular tubes were fabricated by 3D braiding molding technology and resin transfer molding (RTM). Axial impact compression performance tests were conducted on the 3D5D braided composite circular tubes using the Split Hopkinson Pressure Bar (SHPB) at low temperatures (−100°C, −50°C) and room temperature (20°C). The effects of temperature and strain rate on the axial impact compression performance of 3D5D braided composite circular tubes were studied using the Stereomicroscope and SEM. The results show that temperature and strain rate have a significant effect on the axial impact compression performance of 3D5D glass fiber/epoxy resin braided composite circular tubes. Under the low-temperature field, the axial impact compression mechanical properties of 3D5D braided composite circular tubes are better than those at room temperature. With the increase of strain rate and the decrease of temperature, the peak stress, the compression modulus and the specific absorption energy of 3D5D braided composite circular tubes increase to varying degrees. In the low-temperature field, the axial impact compression failure characteristic of the material is brittle fracture and the fracture of the fiber bundle is relatively neat. The degrees of specimens’ failure and deformation become more severe with the increase of strain rate and the decrease of temperature. However, the 3D5D braided composite circular tubes maintain good structural integrity even at high strain rates and low temperatures.