PARAMETRIC STUDY OF INTERFACIAL DEBONDING IN ADHESIVELY BONDED COMPOSITE JOINTS

In composite structures adhesive bonding is preferred to mechanical fa steners because they provide even stress distribution, smooth surface contours and excellent fatigue properties. Interfaces of adherend and adhesive are the potential sources for the initiation of debonding lea ding to failure. In the present work, composite joints are analysed us ing the finite element method for the computation of the strain energy release rate, which is used as a measure for possible debonding. Inte rfaces are modelled by paired nodes and are released one after another in a proper sequence, modelling the crack opening. Joints with variou s values of elastic moduli, thickness of adherend and adhesive, and ov erlap lengths for different crack growth lengths along the interfaces are analysed. Laminae of different fibre orientations and lay-up seque nces are also considered. Failure loads are estimated and material and geometrical parameters and lay-up sequences are suggested.