Moment-rotation behaviour of top-seat angle bolted connections produced from austenitic stainless steel

Use of stainless steel alloys for structural applications could provide a more efficient balance between design life expenses in addition to in-service performance. To achieve safe and economic design rules, an appropriate understanding of the mechanical response of structural components, as well as connection systems produced from stainless steel, is required. Over the last two decades, significant research has been carried out on stainless steel members, but the moment-rotation (M − ϕ) behaviour of stainless steel connections is yet to be thoroughly investigated. Top-seat angle connections are widely used in traditional bare steel constructions due to their ability to transfer both the vertical reaction as well as the end moment, and their behaviour is classified as partially restrained or semi-rigid in nature. The current study investigated the M − ϕ behaviour of austenitic stainless steel top-seat angle bolted connections. The Finite Element (FE) modelling technique using ABAQUS was used to develop appropriately validated numerical models based on the experimental evidence available from the relevant literature. Significant strain hardening exhibited by the austenitic grades was considered in FE modelling. The effects of a number of key geometric parameters such as angle thickness, gauge distance, depth of beam, bolt size and length of angle were considered. The results obtained from the parametric study were used to develop an analytical model based on the power model approach suggested by Richard-Abbott (1975); and the performance of the developed model was also verified. The proposed simple connection model will enable predicting the M − ϕ behaviour of stainless steel top-seat angle bolted connections using easily obtainable geometric and material properties.