列车气动力作用下的声屏障强度分析

发布时间：2018-10-16 19:16

【摘要】：随着高速铁路技术的迅速发展,列车的运行速度越来越快,造成了不可回避的噪声问题。声屏障是降低列车这类移动噪声源问题的重要手段,在高速铁路上有较广泛的应用。目前对声屏障的设计思路基本停留在较大安全系数的静力计算上,这对金属材料的利用率往往较低,并且设计中较少考虑交变的气动载荷对声屏障寿命的影响。因此基于列车风气动载荷的声屏障强度分析是很有必要的。本文的主要工作分为以下三点： 1通过流体控制方程和紊流k-ε模型,利用有限体积法仿真分析了列车通过声屏障的外流场,得到了声屏障上的气动载荷,并拟合了其随速度的变化曲线。气体压力为一个随时间变化且不均匀分布的面载荷。任意点压力随时间呈两个脉冲状变化。声屏障沿高度方向,内侧面压力从下而上变小,外侧面压力从上而下减小。 2通过单向流固耦合技术,将声屏障受到的气动载荷加载为声屏障的受力条件,利用有限元法分析了声屏障的受力情况和变化规律,并得到了应力与速度、中心距的脉谱图。H钢立柱受到弯扭组合变形,弯矩扭矩各经历两次换向。每当列车经过一次,等效应力产生四个脉冲,其中第一个脉冲值最大。等效应力与速度成二次曲线关系。 3根据出现最大应力的节点(危险点)的时间历程曲线,用雨流计数法得出对应工况下的载荷谱。利用材料的S-N(应力-疲劳)曲线和Good-man曲线修正平均应力,采用线性累计损伤理论预测立柱的疲劳寿命。尽管H钢立柱受到的应力不大,但可能出现疲劳破坏,车速和声屏障距离对其疲劳寿命有非常大的影响。
[Abstract]:With the rapid development of high-speed railway technology, the speed of train running faster and faster, causing unavoidable noise problem. Noise barrier is an important means to reduce the problem of moving noise sources such as trains. It is widely used in high speed railway. At present, the design idea of acoustic barrier is based on static calculation of large safety factor, which is often low on the utilization ratio of metal materials, and the influence of alternating aerodynamic load on the life of acoustic barrier is seldom considered in the design. Therefore, it is necessary to analyze the intensity of sound barrier based on the aerodynamic load of train wind. The main work of this paper is as follows: 1 through the fluid control equation and turbulent k- 蔚 model, the flow field of the train passing through the acoustic barrier is simulated and analyzed by using the finite volume method, and the aerodynamic load on the acoustic barrier is obtained. The curve of its variation with velocity is fitted. The gas pressure is a surface load which varies with time and is unevenly distributed. The pressure at any point changes in two pulses with time. Along the height direction, the inner side pressure decreases from the bottom to the top, and the outer side pressure decreases from the top to the bottom. 2 through the unidirectional fluid-solid coupling technology, the aerodynamic load on the sound barrier is loaded into the stress condition of the sound barrier. The stress and variation law of the noise barrier are analyzed by finite element method, and the pulse spectrum of stress, velocity and center distance are obtained. H steel column is subjected to combined bending and torsion deformation, and the moment and torque each undergo two commutations. Each time the train passes by, the equivalent stress produces four pulses, the first of which is the largest. The relationship between equivalent stress and velocity is conic. 3 according to the time history curve of node (dangerous point) with maximum stress, the load spectrum under corresponding working condition is obtained by rain flow counting method. The S-N (stress-fatigue) curve and the Good-man curve are used to modify the average stress and the linear cumulative damage theory is used to predict the fatigue life of the column. Although the stress of H-steel column is not large, fatigue failure may occur, and the speed and the distance of sound barrier have great influence on the fatigue life of H-steel column.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U213.83;TB535

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