Evaluation of stress-strain models for fibre-element analysis of hollow steel tubular columns at ambient and elevated temperatures

Fibre beam element (FBE) is generally used in the simplified simulation of steel hollow tubular columns. However, the accuracy of FBE modelling is greatly affected by the accuracy of the input material models, which should account for the local buckling effects in the simulation of steel tubular stub columns. A few FBE models are available in the literature to simulate steel tubular columns at ambient and elevated temperatures. This study evaluated the material models available in the literature for rectangular hollow steel columns by comparing with test data which covers a wide range of parameters. It was found that the existing equations have certain limitations in predicting steel hollow columns behaviour, such as peak load and corresponding strain, initial stiffness, and/or softening behaviour at ambient and elevated temperatures. Thus, further research is required to develop versatile effective material models for both ambient and elevated temperature FBE simulation of steel hollow tubular columns.