This study deals with the out-of-plane flexural torsional buckling strength of singly symmetric free-standing circular arches with a hollow cross-section. The behavior of such arches is investigated numerically in terms of the out of plane critical elastic buckling load and ultimate load carrying capacity when such arches are subject to a radial pressure that creates uniform axial compression. Prediction methodologies proposed by other researchers for flexural torsional buckling of arches with an I-shaped cross-section, as well as American, European, and Australian code provisions for flexural buckling of compression members are slightly modified and compared with numerically obtained critical elastic buckling loads and ultimate load carrying capacities. All investigations are conducted using validated shell finite element simulations. A parametric study is conducted to evaluate the influence of arch depth, wall thickness, subtended angle, arch radius, yield strength, initial imperfections, and residual stresses on the 3D elastic-plastic behavior of such arches. It is concluded that it is not necessary to use eigenvalue buckling analysis to obtain critical elastic buckling loads for improving capacity predictions and that such loads may be obtained using existing formulations with slight modifications. Additionally, existing code provisions for flexural buckling of compression members may be used with minor modifications to predict the out-of-plane flexural torsional buckling capacity of such arches. Also, prediction methodologies proposed by other researchers for flexural torsional buckling of I-shaped arches may also be used with slight modifications and resulted in the most accurate, consistent, and design appropriate capacity predictions.

本研究涉及具有空心横截面的单对称独立圆拱的平面外弯曲扭转屈曲强度。当这种拱受到产生均匀轴向压缩的径向压力时，根据平面外临界弹性屈曲载荷和极限承载能力对这种拱的行为进行数值研究。其他研究人员提出的用于 I 形截面拱的弯曲扭转屈曲的预测方法，以及美国、欧洲和澳大利亚关于受压构件弯曲屈曲的规范规定略有修改，并与数值获得的临界弹性屈曲载荷进行了比较和极限承载能力。所有调查均使用经过验证的壳有限元模拟进行。进行参数研究以评估拱深度、壁厚、对角、拱半径、屈服强度、初始缺陷和残余应力对此类拱的 3D 弹塑性行为的影响。得出的结论是，没有必要使用特征值屈曲分析来获得临界弹性屈曲载荷以改进容量预测，并且可以使用现有公式稍加修改即可获得此类载荷。此外，可以使用现有的关于受压构件弯曲屈曲的规范规定，稍作修改即可预测此类拱的平面外弯曲扭转屈曲能力。还有，