轴箱吊耳振动测试及共振疲劳评估

Vibration Testing and Resonance Fatigue Assessment of Axlebox Lifting Lug

某线路地铁车辆轴箱吊耳发生多起断裂事故,因此针对该吊耳进行了振动测试、模态结构优化和共振疲劳计算。测试表明吊耳断裂为线路波磨频率与吊耳一阶固有模态频率发生共振所致,并通过仿真分析进行了吊耳模型验证和结构优化。以实测波磨路段动应力为输入,利用窄带疲劳寿命评估方法和Dirlik疲劳寿命评估方法对吊耳寿命进行评估,评估结果与实际基本一致,表明利用窄带法进行共振疲劳寿命评估基本可行;对于共振疲劳,当主频绝对单一时,Dirlik法计算结果与窄带法计算结果一致。

The axlebox lifting lug of a metro vehicle had broken several times,so that vibration test,modal structure optimization and resonance fatigue assessment were carried out for the lifting lug.The test results showed that the reason of lifting lug breakage was the resonance between the corrugation frequency and the first natural mode frequency of the lifting lug.The lifting lug model was verified and the structure was optimized by simulation analysis.Based on the data which was measured on corrugation line,the lifting lug’s fatigue life was evaluated by the method of narrow-band fatigue life assessment and Dirlik fatigue life assessment method,and the assessment result was consistent with actual situation.It showed that the narrow-band method was basically feasible to evaluate the resonant fatigue life.For resonance fatigue,when the dominant frequency was absolutely single,the results of Dirlik method was agree with narrow band method.