WEIGHT-FUNCTIONS FOR CRACKS NEAR THE INTERFACE OF A BIMATERIAL JOINT,AND APPLICATION TO THERMAL-STRESSES

In a thermally loaded bimaterial joint, high stresses occur near the f ree edge of the interface due to the different thermal expansion coeff icients and elastic properties. The thermal singular stress field can be described analytically. In case of a crack in one of the two materi als, another singular stress field occurs in the vicinity of the crack tip. Under linear-elastic conditions the stress field near the crack tip can be described by mode I and mode II stress intensity factors. T he weight function method can be applied to calculate the stress inten sity factors for cracks near the interface. A procedure is described t o determine the weight functions using reference loading cases. These reference loading cases are calculated by the finite element method. T he stress intensity factors are determined for different crack locatio ns and the influence of the elastic constants of the two bonded materi als is discussed. Copyright (C) 1996 Elsevier Science Ltd