Abstract: This paper concerns with static and fatigue behaviour of interlaminar shear in carbon fiber reinforced modified BMI resin matrix composites. The effects of interface with various kinds of resin matrix and different stacking sequence on interlaminar shear behaviour are analysed. The S-N life curves of interlaminar shear fatigue loading are given. The results show that the static and fatigue behaviour is enhanced by modified BMI resin matrix. And the twice-modified matrix is better than once-modified matrix in these behaviour. Typical shear stiffness reduction curve and fatigue damage development curve make it clear that the initial damage increases rapidly then increases at stable rate in the most of fatigue life, until the damage finally increases abruptly to failure. Interlaminar shear damage and strengthen mechanism associated with fractographic features are discussed. Compared with the carbon/epoxy composite, BMI resin matrix composites have good bonding strength between the carbon fibre and matrix, so that improves the ability of fiber to resist the fatigue crack propagation.

Key words: interlaminar shear, fatigue, interface, BMI resin matrix