Effects of tube design on crashworthiness of CFRP thin-walled square beams filled with aluminium honeycomb under axial impact

Using Carbon Fibre Reinforced Plastic (CFRP) thin-walled tubes filled with aluminium honeycomb as automobile energy absorbers is a new idea of energy absorber design. This paper studies the crashworthiness behavior of CFRP filled tubes by using finite element numerical simulation and dynamic impact testing. The influence of tube factors on crashworthiness are analyzed, including wall thickness, tube length, lay-up angle, layer ratio, impact velocity. The results show that, the main factors affecting the energy absorption characteristics under the axial impact are wall thickness, square tube length and lay-up angle. Properly increasing the wall thickness and the tube length can effectively improve the energy absorption capacity. The effect of lay-up angle on F-max, EA and SEA are mixed, so comprehensive consideration is needed in the design. The reasonable tube design can greatly improve the energy absorption capacity of CFRP filled structure.