钢曲杆在高温(火灾)环境下的力学性能分析

Analysis of Mechanical Characteristics of Steel Curved Rods in The High Temperature(Fire) Condition

高温(火灾)环境下大跨度钢曲杆力学性能会发生很大变化,本文根据钢结构、火灾学及力学基本理论,分别以三铰拱、两铰拱和无铰拱这三种形式为研究对象,提出了高温(火灾)环境下大跨度钢曲杆内力计算公式,分析了高温(火灾)下相关参数(线膨胀系数、结构温度、矢跨比、自重等)对大跨度钢曲杆承载性能的影响。研究表明:随着钢曲杆线膨胀系数增大、温度升高、自重增大,钢曲杆的内力增大,钢曲杆承载性能逐渐减小,并通过算例验证了所提方法的正确性,提出了在实际工程中如何提高钢曲杆承载性能的相关措施,可为大跨度钢曲杆抗火设计与分析提供参考。

TMachanics behevior of large span steel curved rod differs a lot in high temperature(fire) condition.Based on the basic theory of steel structure, fire science and general theory of mechanics, three hinged arch, two hinged arch and three kinds of non hinged arch are studied. The internal force calculation formula of the large span steel under high temperature (fire) environment is presented, and the influence of several relative parameters (linear expansion coefficient, structure temperature, ratio of rise span ratio and weight) on the load carrying capacity of large span steel arch in high temperature (fire) condition is analyzed. Research shows that with the increase of the linear expansion coefficient, the increase of temperature, and the weight of the steel bars, the internal force of the steel bars is increased, and the bearing capacity of the steel is gradually reduced,the correctness of the proposed method is verified by a numerical example, and some conclusions are drawn for the fire resistance design of long span steel curved rods. In the practical engineering, the relative measures to improve the bearing capacity of the steel curved rod are put forward.