高速接触线动态疲劳可靠性研究
Investigation on Dynamic Fatigue Reliability of High-speed Contact Wires

接触线在实际运营中长期受到受电弓的冲击，易发生疲劳破坏，对其疲劳可靠性分析具有重要意义，为解决实际统计数据匮乏的问题，提出了一种基于弓网动态仿真的接触线疲劳可靠性评估方法。采用威布尔分布来描述接触线的疲劳寿命，结合其S-N曲线，通过推导建立了接触线疲劳可靠性与使用寿命和应力循环的关系；基于模态分解法建立高速弓网动力学模型，计算接触线最薄弱单元的应力时程；利用雨流计数法统计出每个应力循环的均值和幅值，带入可靠性模型中，绘制接触线疲劳可靠性曲线，并研究了接触线预张力的变化对接触线可靠性的影响。算例中，当使用时间超过9年时，接触线疲劳可靠性将会低于0.98，预张力的增大会导致接触线可靠性的下降。
Contact wire is subjected to fatigue failure under the impact of the pantograph in real operation conditions. It is of great significant to analyze its fatigue reliability. In order to solve the problem of lacking actual data, this article proposes a method of evaluating the contact wire fatigue reliability based on pantograph-catenary dynamic simulation. Weibull distribution is adopted to describe the fatigue life of contact wire. The fatigue reliability expressed by working life and stress cycle is deduced with its S-N curve. The stress cycle of the weakest element is calculated by solving the high-speed pantograph-catenary equation at the basis of modal analysis method. The fatigue reliability curve is drawn by substituting the mean value and amplitude value of each stress cycle obtained by rain flow count method into the reliability model. And the influence of the pre-tension change on the fatigue reliability is studied. And the influence of the pre-tension change on the fatigue reliability is studied. For the numerical example, the fatigue reliability of the contact wire decreases to 0.98 after 9 years. The increase of the pre-tension will result in the loss of reliability