Modelling of Semi-Rigid Joints in Steel-Concrete Composite Frames

This paper introduces a semi-rigid joint model to capture the composite beam-to-column joint behaviour so that the influence of joints on the building frame can be assessed precisely. The beam-to-column joint is modelled using a 6-degree of freedom non-linear connector. Depending on the joint type (e.g., simple, rigid or semi-rigid), connector load deformation behaviour can be represented by axial force-displacement relationship and moment-rotation relationship. This will avoid detailed finite element modelling of joint components to improve the computational efficiency of analysing large three-dimensional (3D) building frame. Analysis of 3D frame shows that the use of semi-rigid joint model predicts less beam deflection and higher load carrying capacity compared to pin-joint model. The incorporation of semi-rigid joint model in 3D frame analysis tends to produce more realistic estimate of frame behaviour compare to model using pin or rigid joints.