Failure mechanism and energy-absorbing characteristics of CFRP thin-walled C-channels subject to axial compression

In order to analyze the failure mechanism and energy-absorbing characteristics of carbon fiber reinforced polymer(CFRP) thin-walled C-channels subject to axial compression, 12 groups of T700/MTM28 CFRP thin-walled C-channels specimens with 3 different layer numbers and 4 different ply orientations were fabricated. The failure modes and load-displacement curves were observed, then the effects of layer number and ply orientation on failure modes and energy-absorbing characteristics were further analyzed by investigating the energy-absorbing characteristics indicator, such as peak load, average load, specific energy absorption, load efficiency. The results show that for specimens with 0° plies, the overall instability occurs so it can not absorb crashing energy. For specimens with 0°/90°, ±45° and 45°/90°/-45°/0°plies, the steady progressive failure and local buckling failure modes are presented. The SEA of C-channel specimens with 45°/90°/-45°/0° plies increases with the layer number increasing and it hence has greater potential for energy-absorbing structure design and application.