温差对磁浮双跨轨道梁变形及振动的影响

发布时间：2018-12-10 09:02

【摘要】：在磁浮轨道交通系统中,对轨道梁的平顺度及振动特性要求非常严格,现有规范规定,受竖向最大温差作用的连续梁,其竖向变形应小于等于单跨跨度的1/6500;受横向最大温差作用的连续梁,其横向变形应小于等于单跨跨度的1/6960;连续梁竖向振动加速度不超过0.35倍重力加速度。本文就温差荷载对双跨磁浮轨道梁挠度变形及动力性能的影响进行了研究分析。运用有限元软件建立双跨轨道梁实体模型,对轨道梁施加极限温差荷载,以热流换热模拟环境温度的影响。结果表明:受最大温差荷载作用的双跨连续梁横向变形随环境温度升高而增大,随梁截面高度增加而增大,且变形大小满足现有规定;连续梁竖向变形随环境温度升高而增加,随梁截面高度增加而增加,且变形大小不满足现有规定,现有规定过于严格。为研究车辆与轨道梁动力性能,建立车-桥耦合振动模型,将由温差荷载引起的轨道梁变形进行拟合后作为双跨连续梁平衡位置曲线,运用FORTRAN语言编写计算程序。结果表明:温度激励使连续梁位移及加速度增大;连续梁竖向动力放大系数随环境温度的升高而增大,随车速的增加而增大,随梁跨度的增加而增大。上海磁浮运营线轨道梁竖向振动时最大动位移为1.892 mm,最大加速度为0.389 m/s2,均满足现有规范,且仍有一定的安全余量。
[Abstract]:In the maglev rail transit system, the requirements for the ride comfort and vibration characteristics of the track beam are very strict. According to the existing code, the vertical deformation of the continuous beam subjected to the maximum vertical temperature difference should be less than 1 / 6500 of that of the single span. The transverse deformation of the continuous beam subjected to the maximum transverse temperature difference should be less than 1 / 6960 of that of the single span and the vertical vibration acceleration of the continuous beam should not exceed 0.35 times of the gravity acceleration. In this paper, the effect of temperature difference load on deflection and dynamic behavior of double span maglev track beam is studied and analyzed. The finite element software is used to establish the solid model of two-span track beam, which is subjected to the ultimate temperature difference load, and the heat transfer is used to simulate the influence of ambient temperature on the track beam. The results show that the transverse deformation of the two-span continuous beam subjected to the maximum temperature difference load increases with the increase of ambient temperature and increases with the increase of the cross-section height of the beam, and the deformation size meets the existing requirements. The vertical deformation of continuous beam increases with the increase of ambient temperature and with the increase of beam cross-section height, and the deformation does not meet the existing regulations, so the existing rules are too strict. In order to study the dynamic performance of vehicle and track beam, the coupled vibration model of vehicle-bridge is established. The deformation of track beam caused by temperature difference load is fitted as the equilibrium position curve of two-span continuous beam. The calculation program is compiled by FORTRAN language. The results show that the temperature excitations increase the displacement and acceleration of the continuous beam, and the vertical dynamic magnification factor of the continuous beam increases with the increase of ambient temperature, the speed of the beam and the span of the beam. The maximum dynamic displacement of the track beam in Shanghai maglev line is 1.892 mm, and the maximum acceleration is 0.389 m / s ~ 2, which meets the existing specifications and still has a certain safety margin.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U441

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