Abstract: It is proved from analytical treatments and computer experiments that the projected conservation relation of the J k vector, found for microcrack shielding problems in brittle homogeneous cases, is also valid for the shielding problems in bimaterial solids, although the characteristic oscillating stress singularity exists near the tip for an interface crack and the tension and shear modes are inherently coupled near the tip. As the relation is shown to be universal, it could be called as the projected c...