Abstract
In this study, critical J-value was used as the parameter of bonding strength criterion of dissimilar material joints with an interface crack. J-value was calculated by finite element method. The effect of several factors (Young's Modulus ratio, Difference in coefficient of thermal expansion, Temperature variations, Crack length etc.) on J-value was discussed. Fracture tests were carried out using specimens that were bonded using an insert material. Critical J-value was analyzed from both breaking load of fracture test and thermal stress induced by temperature variations from bonding temperature to test temperature. This value was not affected by initial crack length and insert material thickness. Therefore, this value was reasonable as parameter of bonding strength criterion of joints. From the results, it was found that this method was valid as the evaluation method of bonding strength of dissimilar material joints.
