Heat transfer modelling of CFRP strengthened and insulated steel tubular columns

The lack of knowledge of the fire performance of CFRP strengthened and insulated steel tubular columns has hindered the CFRP usage in steel columns, which require certain structural fire ratings. In this research, a numerical modelling approach was used to investigate the heat transfer behaviour of CFRP strengthened and insulated steel columns, and thus to enhance the knowledge of their fire performance characteristics. For this purpose, an experimental investigation was also conducted to determine the thermal properties of carbon fibre, adhesive, CFRP and insulation materials at elevated temperatures. These thermal properties were idealized and used to develop heat transfer finite element models in ABAQUS/CAE to simulate the behaviour of CFRP strengthened and insulated steel columns exposed to fire. The developed models were validated by using experimental results and a parametric study was then conducted to investigate the influence of insulation thickness on the heat transfer behaviour. This paper presents the details of this research and the results. It provides the details of the validated heat transfer finite element models and the important thermal properties of CFRP and insulation materials. An approach to determine the fire resistance level of CFRP strengthened and insulated columns is also presented in this paper.