Analysis of composite laminates with imperfect bonding conditions

A multidomain boundary integral formulation for the analysis of composite laminates with imperfect interlaminar interfaces is presented. An imperfect interface refers to a zero-thickness interfacial layer across which displacement discontinuity may occur while interlaminar tractions must remain continuous. The displacement discontinuity is considered through a spring model in order to model the adhesive layer among two adjacent laminae. No auxiliary elements are needed to implement the imperfect interface since the spring coefficients, characterizing the different bonding interface conditions, are taken into account inside the assembled influence matrices. To assess the reliability and the effectiveness of the model some numerical analyses have been carried out on the bending response of composite laminates with different interface bonding conditions. A symmetric cross ply laminate has also been analyzed and the effects of a weak interface on the peel stresses have been pointed out