A Robust K Estimation Scheme using Mesh-Insensitive Structural Stresses

Abstract

In this paper, the applications of a new structural stress method, referred as a mesh-insensitive structural stress method developed recently, in estimating stress intensity factors for welded joints will be discussed. The new structural stress method is based on the considerations of separating an actual stress state into two parts: (1) equilibrium-equivalent part and (2) self-equilibrating part. Both parts are consistent with the far-field stress state with respect to a hypothetical crack location within fracture mechanics context. Therefore, the stress intensity factors (K) can be estimated once the mesh-insensitive structural stresses become available. The method is particularly suited for applications in welded joints in complex structures. In this paper, a brief description of the mesh-insensitive structural stress procedure is reviewed. A robust K estimation procedure is then presented. The new K solution procedures were then validated against a series of well-known K solutions for welded joints in the literature. Finally, discussions are given in terms of the implications of the present solutions in applications in complex structures.