Composite Parameters and Mechanical Compatibility of Material Joints

The elastic behaviour of a bimaterial interface with interfacial cracks, misfit dislocations and interfacial thermal stresses can be described in a simple manner by using the com posite parameters α and β, and the effective modulus of elasticity E*, assuming a plane deformation of ideally bonded isotropic materials. A coefficient K T for the thermally in duced stress intensity at the interface serves as a measure of the mechanical compatibility of two bonded materials. An examination of these parameters for many composite materials shows that the values of the composite parameters α and β are limited to a nar row range and that the material transition can be classified into six groups with regard to their mechanical compatibility.