Abstract
The singularity of the stress field at the tip of a partially closed interface crack is discussed based on a non-uniform spring stiffness model that includes an inverse function of the radial distance from the crack edge. Two distinct non-oscillatory singular stress fields, corresponding to Mode I and II deformations, respectively, are found to coexist. An oscillatory singularity may also appear, but only when the two stiffness intensities are close to each other. This means that the oscillatory singularity exists when the normal and tangential interactions between the upper and lower crack faces are close.
