INTERLAMINAR FRACTURE EFFECTS IN ADHESIVELY BONDED COMPOSITE JOINTS

摘要

The fracture behaviour of adhesively bonded carbon-fibre reinforced composite joints was studied under loading in modes Ⅰ, Ⅱ and mixed-mode Ⅰ/Ⅱ. The failure path in the joints was observed to be either cohesive, in the adhesive layer, or interiaminar, in the composite substrate. Whether cohesive or interiaminar failure occurred was shown to depend upon whether the transverse tensile strength of the composite substrate was exceeded in the joint. A scheme has been proposed to determine the transverse tensile stress in the composite substrates and these values were compared to the measured strengths. Such a scheme correctly predicted the failure paths in the joints tested and correctly predicted that interiaminar substrate failure was most likely to occur in mixed-mode toad ing.