Toward a design method for metal-composite co-cured joints based on the G-SIFs

In this work, a systematic study of the singular stress field in the zone where the interface intersects the free edge surfaces of bonded metal-composite co-cured joints, has been performed. The obtained theoretical, numerical and experimental results have permitted to detect the relationships between the joint configuration and the singular stress field, as well as to implement a new design method based on the so called generalised stress intensity factors. Such a proposed method allows the user to predict the static strength of a generic metal-composite co-cured joint, vs. the main influence parameters as the elastic modulus of the coupled materials, the overlap length, the taper angle, the imbalance, etc. The accuracy of the theoretical and numerical analyses performed in the present study, as well as the reliability of the strength predictions provided by the proposed method, have been tested by means of experimental assessments carried out by using aluminum–GFRP and aluminum–CFRP co-cured double lap joints.