Steel bolted flanged connections in tension: Effects of stiffener configurations

Column-to-column bolted end-plate connections with stiffeners welded on the end plates and column side faces for steel modular buildings were investigated, to understand the effect of stiffener configurations on tensile capacity and stiffness. The connection performance was experimentally examined in tension, focusing on the flexure behaviour responses of the end plates, especially the yield lines on the end plates. Detailed finite element analyses (FEA) were also conducted to model the connection behaviours, considering bolt pretensions, contact behaviours and detailed bolt geometry, showing good comparison with experiments. The experimental and FE studies indicated that stiffeners at locations such as the corners of the steel tube could improve the tensile capacity by about 60%. On the basis of the FE modelling, a comparative study was subsequently performed to clarify the effects of stiffener configurations, end-plate thickness, and number of bolts on the tensile capacities and stiffness of such bolted end-plate connections. The effects of stiffener configuration on tensile capacity were also described in detail, based on yield-line theory. •Bolted end-plate connections with various stiffener configurations for tubular members.•Welded stiffeners for improving connection tensile performance.•Tensile failure of the connections governed by flexural yielding of the end-plates.•Detailed FE analysis parametric study for understanding of connection behaviour.•Yield line pattern on the end-plate analysed to clarify the effect of stiffeners.