Structural behaviour of stainless steel beam-to-tubular column joints

This paper complements previous research conducted by the authors on stainless steel bolted joints and reports the first systematic study on the structural behaviour of stainless steel beam-to-tubular column joints with the use of Hollo-bolts. Six full scale specimens including two flush plate joints, two top and seat cleat connections, and two top, seat and web cleat connections of single-sided beam-to- hollow section column joints have been tested and the results are reported in detail. All specimens were in Grade EN 1.4301 austenitic stainless steel and were designed in such a way that a variety of failure modes could be obtained including plastification of the tubular column face, of the connecting angle cleats or the flush plates. For each specimen the moment-rotation response, the evolution of strains in critical locations of the connections and the separation between the column face and the connected beam was monitored and is reported herein. In parallel with the tests, advanced nonlinear FE models were developed. Following validation against the obtained experimental results, parametric studies were conducted to study the effect of key parameters such as, material grade, column face thickness, end plate/angle cleat thickness and bolt spacing on the stiffness, strength and ductility of the joints. Based on both the experimental and numerical results, it was verified that the connections displayed excellent ductility and attained loads much higher than the ones predicted by design standards for carbon steel joints.