Numerical study on fire resistance of rectangular section stainless steel-concrete composite beam

To investigate the fire resistance of stainless steel-concrete composite beams (referred to as stainless steel composite beam), numerical simulations of rectangular section stainless steel composite beams under fire were carried out. The influences of load ratio, thickness of concrete slab, width of concrete slab, reinforcement ratio of concrete slab, height of stainless steel beam, width of stainless steel beam and span of composite beam on the fire resistance of rectangular section stainless steel composite beams were analyzed. Due to the large coefficient of thermal expansion of stainless steel material, the expansion of stainless steel beam will produce an additional bending moment in the stainless steel composite beam under fire, which has a great influence on the fire resistance of stainless steel composite beams. Finally, a simplified calculation method of temperature field distribution of rectangular section stainless steel composite beam was proposed. To adjust and enlarge the maximum bending moment at the mid-span of stainless steel composite beam, the coefficient of temperature additional bending moment was introduced into the calculation formula of critical temperature of stainless steel composite beams, which effectively improves the accuracy of the fire-resistant design method for stainless steel composite beams.