Experimental study on bolted flanged splice connections for square CFST column

Bolted-flange connections for CFST columns for prefabricated composite structures were investigated to be used in prefabricated multi-story or high-rise buildings. Six column splice connection tests were conducted subjected to combined actions of bending and shear forces, changing with the stiffener numbers and flange thicknesses. A finite element model was built to supplement the results, e. g. the joint stiffness and strength, the bolt tension variation, the contact force between the flanges, the yield mechanics and the failure modes. Based on the results, the joint moment resistance and stiffness would obviously increase after adding the stiffeners. Design recommendations for the connection construction were proposed. Formulas to calculate the moment resistance of the joint were deduced according to the yield of flanges and bolts and validated against test and finite element simulation results.