ABSTRACT
This paper presents a summary of the results of an extensive numerical investigation of elevated temperature resistance of welded steel tubular joints for the cases of axial load and in-plane bending in brace members. The aim of this study is to determine a simple method to modify the joint ambient temperature resistance equations for calculating joint resistances at elevated temperatures. For the failure mode of chord surface plastification, it is not always safe to use the steel yield strength modification factor, due to local second order effects of the chord member It is recommended that for CHS/RHS/SHS T-, Y- and X-joints and Type 1 and 2 EHS joint orientations, with the brace member in compression, the ambient temperature joint strength equation should be modified by the reduction factor for the Young’s modulus of steel. For other cases of brace under axial load, including all joints with brace member in tension, the ambient temperature joint strength equation can be modified by the reduction factor for the yield strength of steel. For welded tubular joints under in-plane bending, the ambient temperature joint resistance equations can be modified by the average value of elevated temperature reduction factors for the Young’s modulus and yield strength of steel.
