地铁DTⅢ型扣件e型弹条疲劳特性理论分析

Theoretical Analysis on the Fatigue Characteristics of the e-type Clip of DTⅢFastener

为分析DTⅢ型扣件系统e型弹条在钢轨波磨条件下的疲劳损伤及其疲劳类型,首先建立包含e型弹条在内的扣件系统局部有限元模型,然后建立车辆-轨道耦合动力学模型,获取单个转向架通过时的钢轨垂向位移时程曲线,以此作为边界条件输入至有限元模型中,获取e型弹条的应变、应力时程变化规律,最后采用相应的疲劳理论对e型弹条疲劳损伤及其疲劳类型展开分析。研究结果表明:e型弹条在钢轨波磨条件下的疲劳损伤最大位置在弹条后拱与跟端相接处;曲线波磨条件下弹条疲劳损伤大于直线波磨,与实际运营情况相符;弹条疲劳寿命大于转变寿命,其疲劳类型为应力疲劳。

In order to analyze the fatigue damage and fatigue type of the e-type clip of the DTⅢfastening system under the condition of rail corrugation,a local finite element model of the fastening system with e-type clip is established,and a vehicle-track coupling dynamics model is built to obtain the vertical displacement-time curve of the rail when a single bogie is passed,which is input into the finite element model as a boundary condition to acquire the law of stress-time and strain-time of the e-type clip.Finally,different fatigue theories are used to analyze the fatigue damage and fatigue type of the e-type clip.The conclusions show that the maximum position of the fatigue damage of the e-type clip under the condition of rail corrugation is located where the arch of the clip meets the heel end;the fatigue damage of the clip under the condition of curve corrugation is greater than that of linear corrugation,which is consistent with the on-site operation;the fatigue life of the clip is greater than its transition life,and its fatigue type is stress fatigue.