Cracks in Strain Gradient Elasticity-distributed Dislocation Technique

The mode III fracture analysis of graded cracked plane in the framework of classical and strain gradient elasticity is presented in this work. Solutions to the problem of screw dislocation in plane are available for classical and strain gradient elasticity theories. Different approaches for the formulation of the strain gradient theory, especially considering the boundary conditions, result in singular and nonsingular stress fields at the crack tip. One of the applications of the dislocation is the analysis of cracked medium via the Distributed Dislocation Technique (DDT). The DDT has been applied extensively in the framework of the classical elasticity. In this article, this technique is generalized for the nonsingular strain gradient elasticity formulation available in the literature. For a system of interacting cracks in classical elasticity, DDT results in a system of Cauchy singular integral equations. In the framework of the gradient elasticity, due to the regularization of the classical singularity, a system of nonsingular integral equations is obtained. Plane with one crack is studied and the singular stress distribution in the classical elasticity is compared with the nonsingular stress components in gradient elasticity theories.