外围悬挂的钢结构螺旋楼梯分析与设计

Structural analysis and design of peripheral suspended steel spiral stairs

为提升某图书馆大堂三跑螺旋楼梯的外观效果,提出外侧矩形截面曲梁设置吊杆的结构布置方案。通过Rhinoceros精确建模,一次性完成细部节点设计。采用有限元软件MIDAS Gen分析了结构内力和变形,并进行构件截面设计。通过整体模态分析和实际工况时程分析,对结构舒适度进行了评价。最后模拟了施工方案,比较了理论计算与安装过程造成的偏差。结果表明:节点细部需仔细推敲;螺旋楼梯内、外侧变形差异较大,休息平台和踏步起到了协调传力的作用,适当加强应力集中部位有利于改善构件的内力和变形;重点关注了支座附近受力状态和中段变形大小;舒适度评价时宜按实际工况进行时程分析;悬挂构件自上而下安装时,建议提供各阶段杆件内力,以便施工调平。

In order to improve the appearance effect of the three-run spiral stairs in the lobby of a library,the structural designer put forward the structural layout scheme of the outer rectangular cross-section curved beams with suspenders.Through the precise modeling with Rhinoceros software,the detailed node design was completed at one time.The finite element software MIDAS Gen was used to analyze the internal force and deformation of the structure and the sections of the component were designed.Through the whole modal analysis and the actual time-history analysis,the structural comfort appraisal was carried out.Finally,the construction scheme was simulated and the deviation between the theoretical calculation and the installation process was compared.Analysis results show five viewpoints:the details of the nodes need careful deliberation;the deformation difference between the inside and outside of the spiral stairs is large,the rest platform and the step play a role in coordinating the transmission of force,and properly strengthening the stress concentration location is beneficial to improve the internal force and deformation of the component;the stress state near the support and the size of the middle section deformation are focused on;the time history analysis should be carried out according to the actual working conditions when evaluating the comfort;it is recommended to provide the internal force of the rods at various stages to facilitate construction leveling.