2008 Volume 34 Issue 3 Pages 102-108
The mode I interlaminar fracture behavior of the composite laminates reinforced with Zanchor process which is a novel through-the-thickness reinforcement technique developed by Mitsubishi Heavy Industries and Shikibo, was studied on the basis of the experimental results using DCB (Double Cantilever Beam) specimens. The effects of the Zanchor reinforcement on the macroscopic fracture toughness and microscopic fracture morphology were mainly focused on. Experimental results demonstrated that the mode I interlaminar fracture toughness was remarkably improved by the Zanchor reinforcement, where the fracture toughness, GIC, increased almost linearly with the Zanchor density, Z. In addition, the fracture toughness, GIC, increased drastically during the early stage of crack growth in the Zanchor reinforced composites, where the interlaminar crack propagated stably accompanied by a large amount of fiber bridgings. The above results suggested that the increase in mode I fracture toughness was the consequence of the fiber bridgings induced by the Zanchor process. The fracture toughness, GIC, could be precisely calculated by using the chord compliance, Cchord, though obvious nonlinearity was observed in the load-displacement responses of DCB specimens.
