Decoupling of Generalized Mode I and II Stress Intensity Factors in the Complete Contact Problem of Elastically Dissimilar Materials

Stress singularity of a complete contact problem is studied herein using an asymptotic analysis. It is considered that a half plane is indented by a semi-infinite sharp wedge for the contact geometry. It is also assumed that the contacting bodies have different elastic properties. It was found that the order of stress singularity is less than 0.5 and varies depending on the wedge angle and material mismatch. The variation in the stress singularity is illustrated in the Dundurs parallelogram. It provides an overall view of the material combination for reducing damage at the contact edge. An analysis is then carried out to evaluate the generalized stress intensity factors (GSIFs) of mode I and II (KI and KII) that calibrate the stress state in the vicinity of the contact edge incorporating the actual conditions. For decoupling the modes, it is developed to select an angle at which a shearing mode disappears for KI and an opening mode disappears for KII. It is found that the decoupling angle for mode I decreases and that for mode II increases as the second Dundurs parameter, β increases.