Analysis and Design of Stainless Steel Bolted Connections

Abstract

The use of stainless steel in construction is steadily growing, with applications designed to exploit its structural properties, durability, appearance and fire resistance. The mechanical behaviour of stainless steel is fundamentally different from that of carbon steel. The stress-strain curve of stainless steel is rounded without a well-defined yield stress and exhibits significant strain hardening at relatively small strains. Nevertheless, design provisions for bolted connections between stainless steel structural members in current international standards are essentially based on the rules for carbon steel with some very limited modifications. As the connections form an essential part of all structural assemblages, a comprehensive understanding of their behaviour is vital for efficient design and consequently better performance of structures. For this reason, an investigation into the behaviour of stainless steel bolted connections has been carried out so as to better understand the response of these structural components. Suitable available test data have been reviewed and replicated using numerical models in order to study the behaviour of lap bolted connections and gusset plate connections in stainless steel under static tensile load. Strain-based criteria were defined to identify three failure modes: net section rupture, bolt shear and bearing failure. The developed FE models were successfully validated against the test results, after which they were employed to meticulously investigate the behaviour of bearing and net section rupture of lap bolted connections, as well as the net section failure of single angles connected to gusset plates. The results demonstrated that the response of stainless steel connections has some different aspects from that of carbon steel. The findings have been used to revise the design rules for net section and bearing capacities in Eurocode 3 Part 1.4. These proposed rules take into account the particular mechanical characteristics of stainless steel and therefore offer an improvement to those currently available.