Mixed Mode Bending Test of the Interlaminar Fracture Toughness of Carbon/Epoxy

摘要

The Mixed Mode Bending (MMB) test for evaluation of the laminate interlaminarfracture toughness under various mixed mode loading conditions is described. The tests were performed on unidirectional carbon/epoxy HTA7-6376C split beam specimens. The MMB fixture is slightly modified to fit the tension machine. The test rig, specimen preparation, and test procedure are described. Both analytical and empirical evaluation methods were used. No significant difference due to evaluation technique was seen in G(sub 1C) for pure mode 1 loading condition but the empirical evaluation of G(sub C) became more unreliable with increasing portion of G(sub 2). Both the single mode values G(sub 1C) and G(sub 2C) were found to be lower than reported by the manufacturer.