钢梁在火灾作用下力学性能及耐火因素研究

Research on Mechanical Properties and Fire Resistance of Steel Girder Under Fire

在火灾作用下钢构件的屈服强度、极限强度及弹性模量都有明显的降低,从而导致钢结构承载能力的下降.通过对钢结构在高温下力学性能的研究,对某钢梁在不同工况下耐火性能进行研究分析,得出钢梁在高温下耐火性能与各因素之间的关系.结果表明:高温下钢梁承载力较常温有显著的降低,其承载力降低之比等于高温下弹性模量之比;荷载的大小和保护层的厚度与极限耐火时间有明显的相关性.

In recent years,steel structure is more and more widely used. The fire protection of steel structure has always been outstanding. Under the effect of fire,the yield strength,ultimate strength and elastic modulus of steel components are significantly reduced,leading to the decline of steel structure bearing capacity. In this paper,through the study of the mechanical properties of steel structure at high temperature,the fire resistance of a steel beam under different working conditions is studied and analyzed,and the relationship between the fire resistance and the various factors of the steel beam at high temperature is obtained. The results show that the bearing capacity of steel girder under high temperature is significantly lower than that at room temperature,and the ratio of reduction of its bearing capacity is equal to the ratio of elastic modulus at high temperature; the magnitude of load and the thickness of the protective layer have a significant correlation with the limit refractory time.