Simplified numerical modelling of rectangular concrete-filled steel columns, beams and beam-columns

[EN] Because of its computational efficiency, simplified numerical modelling is the preferred method to simulate structural frames for routine design. As for concrete-filled steel tubular (CFST) columns, fibre beam element (FBE) modelling is often used in the simplified simulation. However, the accuracy of FBE modelling is greatly affected by the accuracy of the input material models, which should directly account for the interaction between the steel tube and core concrete. In this paper, simple yet accurate material models of steel and concrete are proposed for rectangular CFST columns by utilising a large amount of numerical data generated from detailed three-dimensional finite element modelling of stub columns. The material models are then incorporated into the simplified FBE simulation of rectangular CFST columns, beams and beam-columns. The accuracy of the simplified FBE simulation is verified by a wide range of experimental results on rectangular CFST stub columns, slender columns, beams and beam-columns.