摘要
轮轨滚动激励引起的桥梁振动响应和输入功率是计算桥梁结构辐射噪声的重要参数。时域车轨桥耦合振动分析常用于低频振动分析,但在中高频分析时效率较低。为此,提出一种基于力法原理的频域功率流方法解决这一问题。采用无限长Euler梁或Timoshenko梁建立钢轨部件,采用无限大Kirchhoff板、Mindlin板或有限元模型建立桥梁部件,采用弹簧元件模拟钢轨与桥梁之间的连接扣件,并以弹簧力为未知量建立力法基本方程。对比计算了不同轨桥模型对U梁和箱梁桥振动功率的影响。结果表明:U梁桥面板的剪切效应对桥梁振动功率计算结果影响很大,采用传统的无限大Kirchhoff板模型将导致功率级计算误差达到15 d B,而采用Mindlin板模型可获得良好的计算精度与效率。相对于箱梁实体有限元模型而言,采用Mindlin板模型的误差仍然较大。
It is very crucial to obtain the vibration of a bridge and the power input to it through wheel/rail interactions in order to predict structure-borne noise from the bridge. The time domain train-track-bridge interaction analysis is widely used to solve the low frequency vibration problem of the coupled system. However, its efficiency becomes quite low in the medium-to-high frequency range. This paper then aims to propose a power flow method to tackle the system based on the principle of the force method in a frequency domain. The rail component in the system can be represented by either an infinite Euler beam or a Timoshenko beam. The bridge component can be modeled by an infinite Kirchhoff plate, a Mindlin plate or a finite element model. And the fasteners between the rail and the bridge are considered as a spring-dashpot pairs. The compatibility equation of the coupled system is obtained by regarding the internal forces of the spring-dashpot pairs as unknowns. In the case study, the vibration power of a U-shaped girder and a box girder is calculated with various models for the rail and the bridge components. The results show that the shear effect of the bridge deck significantly influences the power input to the U-shaped girder. The use of a conventional Kirchhoff plate model can lead to a calculation error of 15 d B, while the adoption of a Mindlin plate model can gain both high accuracy and efficiency. A Mindlin plate model still produces large computation errors compared with the finite element model of a box girder using volume elements.
出处
《工程力学》
EI
CSCD
北大核心
2016年第12期112-118,127,共8页
Engineering Mechanics
基金
上海市自然科学基金项目(15ZR1442800)
关键词
车轨桥耦合振动
噪声
功率流方法
无限大板
有限元法
train-track-bridge vibration
noise
power flow method
infinite plate
finite element method
