Analysis of load and non-load-carrying fillet welds using HBIEs

In order to obtain the accurate stress intensity factors of crack problem, a finer mesh is usually required in boundary element analysis since the stress (or displacement) solution is not accurate enough, especially near a crack tip. In this study, hypersingular boundary integral equations (HBIEs), combined with a multi-zone technique and traction singular quarter-point element, are implemented to evaluate the accurate boundary stress components especially near the crack tips. The boundary stresses are then used to calculate stress intensity factors by a stress extrapolation method. Numerical results are presented for an edge cracked plate and the stress intensity factors estimated by other methods are compared. Moreover the sensitivity to element mesh and stability to crack lengths are investigated. Finally, the stress intensity factors of load-carrying and non-load-carrying fillet welds are calculated, and the effects of weld size and attachment thickness on the stress intensity factors are analyzed. (C) 1997 Elsevier Science Ltd.