Abstract
The crack propagation behavior of CFRP laminates reinforced with Zanchor was experimentally investigated to find out the toughening mechanism under the mode II loading. The Zanchor is a novel technique of out-of-plane reinforcement to improve the interlaminar strength by entangling in-plane fibers in the through-thickness direction using special needles. Experimental result demonstrated that the effect of Zanchor process was remarkable for the improvement of mode II interlaminar fracture toughness of composite materials, where the fracture toughness proportionally increased with the Zanchor density. Moreover, broken traces of the fiber bundles oriented to the through-thickness direction were observed, whereas no fiber bridgings. Therefore, it was revealed that the key factor of the increase in mode II fracture toughness would be the breaking energy of fiber bundles, which was different from that under mode I loading.
