Analysis of Stress Concentration at Longitudinal Attachment

Following ICOM’s participation in the redaction of a new recommendation for the evaluation of existing railway-bridges, in collaboration with the SBB/CFF, new questions have been raised. Among those, the influence of a welded longitudinal attachment ends shape on its fatigue behaviour was of particular interest. Indeed, this detail has low fatigue strength (as low as detail category 56 according to SIA 263 [SIA 263]) and the possible shape improvements that are given in the code are costly to fabricate. Therefore, the pilot study presented in this report was initiated with the objective to better understand the influence of the attachment shape on the stress concentration and fatigue life of the detail. In order to achieve this objective, the following steps were carried out: • Literature review on study of existing SCF solutions (2000-2003); • Boundary Elements Modelling (BEM) of reference cases; • Study of the influence of the attachment angle, shape, length on the SCF; • Study of the influence of the attachment angle, shape, length on the SIF at various depths. The scope of this study is limited to longitudinal attachment welded onto a plate (that is perpendicular and not to the edge of the plate), under tensile stress field.