高温下受弯钢梁的弹塑性弯扭屈曲分析

基于弹塑性理论,通过建立钢梁截面的弯矩曲率关系作弯矩作用平面内的弹塑性分析等几个步骤,对火灾高温作用下受弯简支钢梁在弹塑性阶段的弯扭屈曲性能变化进行了分析,给出了钢梁的临界屈曲弯矩的计算表达式。通过算例分析了钢梁弹塑性阶段临界屈曲弯矩随温度的变化,并利用ANSYS有限元软件模拟了钢梁在火灾燃烧不同时刻的竖向变形。结果表明,随着温度的升高,钢梁弹塑性阶段的临界弯矩呈现出逐渐降低的趋势,而其竖向变形则逐渐增大,文中对这2个变量在不同温度条件下的具体变化情况分别进行了详细的分析和描述。

Flexural-torsional Buckling Analysis of Steel Beams in High Temperature

Flexural-torsional buckling of simply supported steel beams in high temperature was studied based on elastoplastic theory. The flexural-torsional buckling critical moment equations were driven. The derivation steps contain： establishing the relationship between bending moment and curvature, making elastoplastic analysis in bending moment plane. An example was provided to analysis the variation of the critical buckling moment with temperature in the elastoplastic stage. ANSYS software was used to simulate the vertical deformation of the steel beam in differ- ent burning times. It is known that the critical moment in the elastoplastic stage reduces with the temperature rise. While the vertical deformation of the steel beam increases with the temperature rise. The variation details of the mentioned two variables can also be found in this paper.