基于模态应力的转向架关键悬挂件振动疲劳研究

Vibration Fatigue of Key Suspension Parts of Bogies Based on Modal Stress

通过建立构架关键悬挂件振动疲劳分析模型,采用模态叠加法,获得基于模态应力的构架关键悬挂件应力功率谱,并推导出结构应力的概率分布函数,并以IEC 61373标准谱和实测加速度谱为激励,利用线性疲劳损伤准则获得结构振动疲劳寿命。研究结果表明:关键悬挂件结构在IEC 61373三向加速度各激励5 h后,疲劳累积损伤值最大为1.58;在实测武广线加速度激励下,疲劳寿命为297万km;基于模态应力的分析方法能够有效地考虑激励频率与结构自身频率的振动关系,进而获得更准确的疲劳寿命。

The vibration fatigue analysis model of the key suspension parts of bogie was established, the stress power spectrum of key suspension parts bases on modal stress was obtained by modal superposition method, and the probability distribution function of the structural stress-strain range was deduce, moreover, the fatigue life of the structure was obtained in the condition of IEC 61373 standard spectrum and measured acceleration spectrum as the excitation by using the linear fatigue damage criterion. The results showed that the critical fatigue damage value of the suspension structure was 1.58 after three-direction acceleration of each incentive 5 hours of IEC 61373. Under the actual measured excitation of the acceleration of the Wuhan-Guangzhou line, the fatigue life was 2.97 million kilometers. The analysis method based on modal stress effectively indicated the relationship between the excitation frequency and the vibration frequency of the structure itself, by which the more accurate fatigue life prediction could be obtained.