钢结构人行天桥自振频率模态分析研究  

Modal analysis and research on the natural frequency of steel pedestrain bridge

作　　者：钱若霖 黎豪 王劭琨[1] QIAN Ruolin;LI Hao;WANG Shaokun(Civil Engineering College,Shaanxi Polytechnic Institute,Xianyang 712000,Shaanxi China)

机构地区：[1]陕西工业职业技术学院土木工程学院,陕西咸阳712000

出　　处：《粘接》2022年第3期116-119,共4页Adhesion

基　　金：陕西工业职业技术学院科研基金重点项目(项目编号:2020YKZX-017)。

摘　　要：城市人行天桥多采用钢结构设计,避免共振,其自振频率应不小于3 Hz;以某一字形钢结构人行天桥为研究对象,从理论计算方法确定影响自振频率的3个影响参数,通过有限元建模分析计算不同跨径、梁高及铺装各参数扰动下,天桥的一阶模态自振基频变化规律特点,并对结构的前5阶自振频率及振型特征研究。结果表明:不同模态下结构的自振频率首先出现在刚度较小的方向和部位,竖向和横向刚度均应符合设计要求;天桥设计阶段,应从减小跨径、增加梁高以及减小铺装质量对桥梁自振频率加以控制,使其满足规范动力特性要求,提高安全性。Urban pedestrian bridges are mostly designed with steel structure.In order to avoid resonance,the natural vibration frequency should not be less than 3Hz.Firstly,the three influencing parameters that affect the natural frequency are determined from the theoretical calculation method.Through the finite element modeling analysis and calculations under different spans,beam heights and paving parameters,the characteristics of the first-order modal natural fundamental frequency change of the flyover,and the first five-order natural frequency and mode shape of the structure feature research.The results show that the natural frequency of the structure under different modes first appears in the direction and position with less rigidity,and the vertical and lateral rigidity should meet the design requirements;during the design stage of the overpass,the span should be reduced,the beam height should be increased,and the pavement quality should be reduced so as to meet the requirements of the normative dynamic characteristics and to improve safety.

关 键 词：钢结构 人行天桥 有限元 自振频率 

分 类 号：U448.11[建筑科学—桥梁与隧道工程]