单轴对称工字形截面圆弧拱的屈曲分析

Buckling of Mono-symmetric I-section Circular Arches

根据文献[1]提出的任意开口薄壁截面圆弧曲梁的翘曲位移表达式，本文利用能量原理导出了单轴对称工字形截面拱的稳定平衡方程。文中主要对工字形截面拱在均布径向荷载 (均匀受压 )和两端作用大小相等、方向相反的端弯矩 (均匀弯曲 )条件下的弯扭屈曲进行分析，给出临界荷载的理论解答；考虑了工字形截面不同放置时拱失稳模式的不同，分析截面不对称性对临界荷载的影响，并与已有的文献进行比较。

The flexural-torsional buckling of arches has been investigated theoretically by a number of authors.But most papers are restricted to double- symmetric cross- sections.Starting from warping displacement for arbitrary thin- walled curved beams in Ref.[1],the principle of energy is applied to derive the differential equation of stability for mono- symmetric I- section arches.Rigorous solutions are obtained for arches subjected to uniformly distributed radial load as well as to equal and opposite end moments.Effects of different laying positions and of asymmetry of cross-section on buckling loads are included.The solutions are compared with previous theoretical results.