Numerical study of lean duplex stainless steel plate girders with stocky flanges and slender unstiffened webs under bending

摘要

The behaviour and ultimate strength of lean duplex stainless steel plate girders under bending arernstudied in this paper. Lean duplex stainless steel I-section plate girders (LDIPGs) with stocky flanges and slenderrnunstiffened webs are prone to several buckling phenomena (local, lateral-torsional) and, in particular, to Lateral-rnDistortional buckling (LD). Firstly, shell Finite Element (FE) models are validated by means of comparisonrnwith experimental test results available in the literature. Secondly, these models are used to unveil the structuralrnbehavior and ultimate strength of LDIPGs subjected to uniform bending. After that, the LDIPGs are selectedrnon the basis of three key parameters: the radius of gyration of the compression flange, the section modulus andrnthe unbraced length. Finally, the numerical results are compared with predictions given by AS4100 and EC3. Itrnis found that the EC3 provides conservative predictions for the LDIPGs under bending, with a relatively highrnmargin of safety. In order to reduce this difference, the imperfection factor associated to buckling curve (c) isrnrecommended to be used in the scope of the design method provided by EN 1993-1-4.