人行钢桁架桥动力特性及反应谱分析

摘要

In order to study the characteristics of pedestrian steel truss bridge vibration and dynamic response under seismic action ,a finite element model of the bridge is built by ANSYS to conduct modal analysis and response spectrum analysis ,and the peak value responds of displacement at key sections are obtained .The results indicate that pedestrian steel truss bridge is more susceptible to vibration than railway truss bridge ,and the torsion deformation appears earlier ;pedestrian steel truss bridge is prone to the horizontal and vertical displacement ,and the mid‐span displacement response is larger with the top chord of displacement response than the lower chord large in seismic response spectrum .The conclusions can provide the reference basis for the seismic design of pedestrian steel truss bridge .%为研究人行钢桁架桥动力特性及在地震作用下的动力响应，运用ANSYS对某人行钢桁架桥进行模态分析，用反应谱分析法对其进行三向激励地震响应分析，得到关键截面及桁架杆件的动力响应。分析结果表明：人行钢桁架桥较铁路钢桁架桥更易发生振动，且扭转变形出现较早；在地震反应谱作用下，人行钢桁架桥较易出现横向及竖向位移，且跨中位移响应较大，上弦杆位移响应较下弦杆大。