Imperfection analysis of austenitic stainless steel plate girders failing by shear

The austenitic grades nowadays feature most significantly within the constructional industry. Accordingly, the current paper is concerned with shear failure mechanism characteristics of this type of plate girder, which has not been completely investigated. An imperfection finite element analysis for complete austenitic stainless steel plate girders of grade EN 1.4301 (304) is conducted herein by using the ABAQUS 6.6 program. Two different initial imperfection magnitudes of h w / 100 000 and h w / 100 are included in the model, where h w denotes the web-depth of the plate girders. An arbitrary small initial imperfection value of h w / 100 000 is incorporated in an attempt to determine a bifurcation-type buckling load. h w / 100 is the maximum value allowed by the Bridge Welding Code (AASHTO/AWS 2002). The austenitic stainless steel material is simulated herein based on the two-stage full-range stress–strain material curve introduced by Rasmussen. Fifty eight I-shaped austenitic stainless steel plate girders, which are transversely stiffened and having an equal depth of 1000 mm in a span of 4 m, are considered and parametric studies vis-à-vis flange width-to-web depth ratio, flange-to-web thickness ratio and web plate slenderness are carried out. The results of the finite element modelling showed, generally, that the design equations specified by the European specifications are conservative for the design of austenitic stainless steel plate girders of the maximum imperfection amplitude; h w / 100 . At the end, an adjustment is made to the European specifications that is accurately found to represent the behavior of the austenitic stainless steel plate girders better than the existing equations.