水平弹性支承圆弧钢拱的弹性屈曲分析  

IN-PLANE ELASTIC BUCKLING OF STEEL CIRCULAR ARCHES WITH HORIZONTAL SPRING SUPPORT

作　　者：杨洋[1] 童根树[1] 

机构地区：[1]浙江大学土木工程系,浙江杭州310058

出　　处：《工程力学》2011年第3期9-16,共8页Engineering Mechanics

摘　　要：钢拱常支承于其他结构上,拱脚受到弹性约束并出现水平位移,弹性约束会显著影响拱的力学行为。该文得到了水平弹性支承拱在沿弦长均匀分布的面内竖向荷载作用下的内力及位移的解析解,构造了一个无量纲化柔度系数。利用这个参数,对线性解进行分析,提出了计算跨中轴力和拱脚支座位移的理论公式。根据跨中轴力大小,提出了在线性计算范围内划分拱与拱形梁的标准。分析了支座弹簧刚度对扁度不同的拱的内力分布的影响。利用有限元程序,分析了拱的分支屈曲模态、临界荷载及跨中临界轴力与支座刚度的关系,得到了拱由反对称屈曲转变为对称屈曲时柔度系数的界限值,提出了临界荷载和临界轴力与弹性柔度系数的关系式。An arch is often connected with other structures that provide elastic restraints to the arch.These elastic restraints significantly influence its behavior.The analytical solutions of horizontally elastically supported arches that are subjected to vertical loads uniformly distributed along the arch chord are obtained.A dimensionless elastic flexibility factor is introduced.By analyzing the linear analytical solutions and using the flexibility factor,a simple analytical formula for the mid-span axial force and displacement of support is proposed,and criterions that distinguish between arches and arched beams are suggested.The effects of the stiffness of the horizontal end restraint on the distribution of internal forces,in-plane buckling mode and buckling load of arches are studied.A limiting flexibility factor that distinguishes between the in-plane anti-symmetric bifurcation mode and symmetric snap-through mode is presented,and the formula for buckling mid-span axial forces is proposed.

关 键 词：圆弧拱 水平弹性支承 临界荷载 屈曲 弹性柔度系数 

分 类 号：TU311.2[建筑科学—结构工程]