Analysis of stress intensity factor for normal crack approaching weldbead on simplified compact tension specimen

Abstract

This paper presents a finite element analysis of stress intensity factor for a compact tension specimen under residual welding stress. The crack front is considered normal to the weldbead while the residual stress distributions are chosen from two mathematical functions satisfying the physical requirements peculiar to weld joints. Both these functions are tested to give identical results. The effects of crack sizes and weldbead locations on stress intensity are also closely examined. For constant crack length, an interesting feature (in close agreement with earlier work) is noted here that the stress intensity attains a maximum value when the weld centre line is located eccentric to the crack front, at an approximate distance equal to the half width of tension zone of the residual stress distribution. Further, the minimum value occurs when the weldline nearly approaches the extreme plate edge ahead of the crack tip. The present analysis will be useful for further insight into practical problems.