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高速铁路接触网在随机风场的作用下产生短周期变化的应力循环,影响接触网的疲劳寿命。本文采用Davenport和Panosfsky功率谱分别模拟适用于接触网系统的水平和竖直方向上的脉动风时程,推导了作用在接触网上的气动力。在有限元分析软件MSC-Marc中建立高速铁路接触网有限元模型,通过非线性有限元求解得到随机风场下接触线各单元的应力时程。运用改进的雨流计数法对疲劳应力谱进行统计处理,并经Goodman直线修正,得到每个应力循环的等效应力幅值。基于Palmgren-Miner线性疲劳累积损伤准则,对接触线特征单元的疲劳寿命进行估计。研究结果表明:在强风地区,脉动风对接触网风振疲劳影响较为显著;接触线的风振疲劳不利位置出现在定位点和吊弦点处;风攻角决定了接触线风振疲劳不利位置的具体分布。研究结果可为强风地区接触网疲劳设计、日常维护及故障分析提供依据。
The catenary of high-speed railway produces short-cycle stress circulation under the action of random wind field and affects the fatigue life of catenary. In this paper, Davenport and Panosfsky power spectra are used to simulate the fluctuating wind-time in the horizontal and vertical directions of the catenary system respectively, and the aerodynamic forces acting on the catenary are deduced. In the finite element analysis software MSC-Marc, the finite element model of the high-speed railway contact net is established, and the stress time history of each unit of the contact line under the random wind field is obtained by solving the nonlinear finite element. Applying the improved rain flow counting method, the fatigue stress spectrum is statistically processed and corrected by Goodman linear equation to obtain the equivalent stress amplitude of each stress cycle. Based on Palmgren-Miner linear fatigue cumulative damage criterion, the fatigue life of contact elements is estimated. The results show that in the areas with strong winds, the fluctuating wind affects the wind-induced fatigue of the catenary more obviously; the unfavorable position of the wind-induced fatigue of the contact line appears at the locating point and the hanging point; the wind attack angle determines the unfavorable position of the contact line The specific distribution. The results provide the basis for fatigue design, routine maintenance and fault analysis of catenary in strong wind area.