THE EFFECT OF AXIAL AND ROTATIONAL RESTRAINTS ON THE PERFORMANCE OF COLD-FORMED STEEL BEAMS SUBJECTED TO FIRE

摘要

This paper is mainly aimed at the structural performance of compound cold-formed galvanized steel beams under fire conditions, based on the results of a large programme of experimental tests and numerical simulations, using the advanced finite element program ABAQUS.The main objective of this research was to assess the failure modes, the critical temperature and the critical time of the studied beams.Other important goals of this research work were also to investigate the influence of the cross-sections (C, lipped-I, R and 2R beams) and, above all, of the axial restraint (0, 0.45, 1, 7.5, 15, 30, ∞ kN/mm) to the thermal elongation of the beam and the rotational restraint at beam supports (0, 15, 150,300, 1200 and ∞ kN.m/rad) on the fire resistance of this kind of beams.