面外支撑非均匀布置的 箱型与圆管截面拱平面外弹性屈曲

在面外设置离散支撑,是建筑与桥梁工程设计中提高钢拱面外稳定性采用的有效措施。该文研究了面外支撑沿拱轴线非均匀布置时,箱型与圆管截面两铰拱的平面外弹性屈曲性能。该文首先将拱段间的相互约束作用等效为拱段两端的约束弹簧,采用数值拟合法获得了被约束拱段的平面外弹性屈曲荷载；此后借鉴压弯直构件端部弯矩与转角关系,提出了支撑间拱段的相互约束作用计算方法,并由此得到了面外支撑非均匀布置时,钢拱的平面外弹性屈曲荷载迭代计算步骤。根据该文提出的方法所获得的离散支撑钢拱的平面外弹性屈曲荷载与有限元计算结果吻合较好。

OUT-OF-PLANE ELASTIC BUCKLING OF CLOSE-SECTION STEEL ARCHES WITH NON-UNIFORM DISTRIBUTED LATERAL BRACINGS

Arches in buildings or bridges are usually arranged with distributed lateral bracings to improve their out-of-plane stability. This paper presents the out-of-plane elastic buckling behavior of close-section arches with non-uniform distributed lateral bracings. Firstly, the arch segment between two adjacent lateral bracings is simplified as an equivalent beam with elastic restraints at two ends to simulate interactions with adjacent arch segments, and out-of-plane elastic buckling load of the restrained arch segments is obtained by a numerical method. Referring to the relationship between the end moment and end rotation of a straight beam, the end restraints resulting from adjacent arch segments are considered, and the out-of-plane elastic buckling load of the restrained arch segment subsequently can be obtained by using an iterative calculation method. The out-of-plane buckling loads of steel arches obtained agree well with their finite element numerical results.