In this paper, the J-integral for an interfacial crack by thermal stress that developed during the cooling of the dissimilar material joint is studied. The thermoelastic analysis of J-integral for the bonded joint with an insert layer is performed using the finite element method. The effect of insert layer on the J-integral under the thermoelastic condition is discussed. It is found that the J-integral have three types of variation with an increase of insert layer thickness. The variations of J-integral with an increase of insert layer thickness are dominated by the nondimensional parameter (αC-αB)/(αA-αB) that expressed the relation in magnitude of coefficients of linear expansion and the ratio of Young's modulus (EA/EC). As a result, it is possible to predict the variation of J-integral with an increase of insert layer thickness by using these dominant parameters.
