Modeling impact compressive behaviors of 3D woven composites under low temperature and strain rate effect

Abstract

Dynamic compressive damages of 3D woven composites in low temperature environments are crucial for the design of engineering structures in cryogenic applications. This study presents the compressive damage behaviors of 3D angle-interlock woven composites under low-temperatures. We developed a homogeneous model incorporating the strain rate effect and thermo-mechanical coupled constitutive relation to numerically analyze compressive damages at low temperatures. Dynamic compression tests were conducted on split Hopkinson pressure bar (SHPB) apparatus with strain rates ranging from 300 to 1500/s at temperatures of 20 °C, −40 °C, and −80 °C, respectively. We found that the compressive stiffness and strength are more temperature-sensitive along the out-of-plane direction, while they exhibit greater sensitivity to strain rate along the in-plane direction. The failure mode is characterized by shear failure along the out-of-plane and warp directions, and delamination along the weft direction. The test results and finite element analyses (FEA) show that the 3D woven composites exhibit brittleness at low temperatures and experience more severe compressive damages compared to those at room temperatures. Importantly, we observed accumulations of inelastic heat in the compressive damage zone, indicating that the compressive damages are also converted into thermal energies under low temperatures.