大跨度弧形悬吊楼梯的动力特性研究

Dynamic Performance Analysis for a Large-Scale Cambered Suspended Stair

大跨度悬吊楼梯的跨度大、约束少、整体刚度较柔，其结构的动力特性分析是寻求控制结构设计关键因素的重要途径。文中结合某大跨度弧形悬吊楼梯的结构特点，采用壳、空间曲梁及杆单元建立了有限元力学模型，并根据模态分析结果，得到楼梯结构的主要自振频率和振型分布。分析表明，其低阶自振频率避开了人步行频率范围1～3Hz，低阶振型主要为竖向弯曲和扭转形式。对该楼梯自振性能的分析为进一步优化结构设计提供了技术依据。

The large-scale cambered suspended stair is a flexible structure due to large span, lack of constrains. It is significant to analyze structural dynamic performance for seeking the key factors to control the structural design. In this paper, based on structural features of a large-scale suspended spiral stair, its finite element model was established by shell elements and beam elements. Secondly, the mode analysis for the stair body was conducted. The nature frequencies and vibration modes of the structure were analyzed. The results show that lower order natural vibration frequencies are apart from the foot-crossing vibration range 1～3 Hz, and the main low order vibration modes are the combinations of vertical bending and torsion. The results provide basic data for further structural design.