Structures’ load resistance is reduced when subject to high temperatures in fire. Nevertheless, it is not enough to take into account strength and modulus of elasticity reduction. One must know with great accuracy the behaviour of the structures including the realistic boundary conditions at high temperatures, in order to determine for safe and of low cost solutions. This work is intended to analyse the behaviour of steel beams under uniform temperature rising. It covers beams under several uniform load levels and three boundary conditions: simply supported (pin-roller), simply supported with axial restraint (pinned-pinned) and both ends fixed (fixed-fixed). The variation of deflection, critical temperature, bending moment, normal force and stresses, with the temperature is presented. The analyses were made with the aid of ANSYS computer software taking into account material and geometric non-linearities and the variation of the stress-strain diagram with the temperature.
fire safety; non-linearity; Ansys; structures; steel beam
