Behaviour of top-seat double web angle connection produced from austenitic stainless steel

Abstract

Beam-to-column connections are regarded as one of the critical elements in structures, especially in the case of bare metallic frame construction, as the overall structural performance is highly influenced by the connection behaviour. Significant research on stainless steel members has been reported in the recent past, but research on beam-to-column connections is still scarce. This paper presents an experimental and numerical investigation on the moment-rotation (M-φ) behaviour of a top-seat with double web angle (DWA) connection produced from austenitic stainless steel. A comprehensive investigation on the elasto-plastic deformation patterns observed in individual connection elements has been reported to gain in-depth knowledge in assessing overall stiffness, strength and rotational capacity of the considered connection type. Beam and column sections, as well as the connecting angles and fasteners used in the experiment, were produced from austenitic stainless steel AISI 316 L (equivalent to EN 1.4301). Significant strain hardening, as characterised by stainless steel, was observed throughout with the top angle experiencing most significant deformations. 3D finite element (FE) model was developed to replicate the observed experimental behaviour, and good agreement was observed between numerically obtained results and experimental observations. Based on the experimental and numerical results, semi-rigid connection behaviour was recognized for stainless steel alloy to lay a foundation for the development of the top-seat DWA connection. The observed behaviour for the considered stainless steel connections was compared with those obtained analytically for equivalent carbon steel connections; this comparison demonstrated enhanced ductility and significantly higher plastic moment for stainless steel connections.