Effect of tailored plies on the energy absorption capability of square CFRP tubes with discontinuous fibers

Research on carbon-fiber-reinforced plastic (CFRP) composite laminates shows that advanced pseudo-ductility can be obtained using a cut-ply approach. This study investigates the energy absorption capability of CFRP square tubes with overlapping discontinuous plies. The cutting-angle, α, which can be used as a design variable, is considered and controlled to cut both spacing and density. Quasi-static axial compression tests were conducted to investigate the failure process, crashworthiness and the corresponding energy-absorption mechanism. The results indicate that the cutting angle has a significant effect on the energy absorption. Increasing the cutting angle increases the specific energy absorption from 50.8 J/g to 74.1 J/g. Compared to one sample (56.2 J/g), the specific energy absorption increases by 32%. This study also indicates that the energy absorption of composite tubes can be tailored by adjusting the position of the cuts.