Thickness effect of carbon nanotube interleaves on free-edge delamination and ultimate strength within a symmetric composite laminate

Abstract This paper utilizes carbon nanotube (CNT) buckypaper (BP) as a modified interleaf and incorporates it into the potential delaminated interfaces within the [±θn]S laminates, and then how the CNT BP affects the interlaminar stress and induces free-edge delamination is considered. According to the measured in-put mechanical parameters, a numerical model is firstly developed. Results show that the thickness of the CNT-based interleaf has an obvious effect on the interlaminar stress and corresponding delamination. It just changes the relative value of stress or strength but doesn’t change the patterns of stress distribution or delamination. More importantly, the CNT-based interleaf with a reasonable thickness would significantly decrease the interlaminar stresses (less than 16 μm), delay initiation of delamination and enhance the ultimate strength (less than 40 μm) of the laminates. Simultaneously, the obtained experimental results are coherent with the numerical results, which further prove the thickness effect of the CNT-based interleaf.