Effects of truss behavior on critical temperatures of welded steel tubular truss members exposed to fire

摘要

This paper presents the results of a numerical investigation into the behavior of welded steelrntubular truss at elevated temperatures. The purpose is to assess whether the current method of calculating trussrnmember limiting temperature, based on considering each individual truss member and using the member forcernfrom ambient temperature analysis, is suitable. Finite Element (FE) simulations were carried out for CircularrnHollow Section (CHS) trusses using the commercial Finite Element software ABAQUS. The results of thernnumerical parametric study indicate that due to truss undergoing large displacements at elevated temperatures,rnsome truss members (compression brace members near the truss centre) experience large increases in memberrnforces. Finally, this paper proposes and validates an analytical method to take into consideration the additionalrncompression force due to large truss displacement. This is based on assuming a maximum truss displacement ofrnspan over 30.