Application of the Component Method to Steel Joints under Fire Loading

Abstract

Recent research [1] on the behaviour of steel structures under fire loading highlighted the influence of joint behaviour on the overall response of the structure. The lack of experimental results on the response of steel joints under fire conditions and the use of numerical models relying on empirical relations established from tests either at room temperature, or for a limited range of (low) temperatures, has led to a simplistic specification from the current codes of practice. In fact, according to Eurocode 3, Part 1.2 [2] and Annex J [3], the concentration of mass within the joint area, when compared to the connecting members, delays its temperature increase, therefore suggesting that joints could be disregarded under fire conditions. However, in contrast to the EC3 specification, recent experimental results [4,5] have highlighted the need to evaluate the behaviour of steel joints at elevated temperatures, since they exhibit a pronounced reduction of strength and stiffness that clearly affect the global response of the structure.