複合材料積層板における隣接層内き裂の干渉

抄録

Contiguous-ply cracking behavior induced by existing transverse cracks in composite laminates is investigated. When transverse cracks occur and accumulate in one ply, matrix cracking in contiguous plies is induced one after another. In this study, stress analytical method of laminates with obliquely-crossed transverse cracks (e.g. [S/θ_m/90_n]s laminates with transverse cracks in θ- and 90-plies) is presented and combined with finite element analysis, which enables geometrically parametric analysis using a single discrete model. Stress analyses of [0/θ₂/90]s laminate with cracks in θ- and 90-plies are performed under various conditions of angle θ and θ-ply crack length. Moreover, energy release rates associated with θ-ply crack propagation are calculated. These results suggest that presence of 90-ply cracks affects θ-ply crack propagation in fiber direction, especially through mode-I energy release rates, depending on angle θ. The formation of 0-ply cracking in [0/θ₂/90]s laminate with cracks in θ- and 90-plies is also discussed.