Traction Structural Stress Method Estimates for Corrugated Steel Web Beam Flange Weld Joints

The fatigue behaviour of a corrugated steel web beam is greatly affected by the stress characteristics of the flange weld joint. Due to the stress concentration and local geometry, the stress characteristics and the fatigue lives of such joints are prone to be conservatively predicted using traditional methods. In this paper, the finite element models are developed for the flange weld joints to compare critical stress distribution with respect to different curvature sections connecting the parallel and inclined web folds where fatigue cracks are prone to take place. Compared to other direct output modelling stresses, the traction structural stresses results are shown to be less sensitive to local mesh refinement. The influence of varied curvature section and flange thickness on the stress characteristics of the flange weld joints are explored. In contrast, more reduction of the traction structural stress can be achieved with the decrease of the corrugation angle which can be regarded as the primary factor for relieving the local stress concentration. The accuracy of the traction structural stress method-based finite element analysis for the flange weld joint in the corrugated steel web beam was validated and proven to be more effective in relation with fatigue failure lives as compared with traditional nominal stress-based method. The engineering fatigue assessment of these flange weld joints can be simplified from the traction structural stress method accounting for the stress concentration at the weld toe and the thickness variation.