汽车悬架承载梁焊接结构疲劳分析

Fatigue analysis method for welded structure of suspension bearing beam

为了有效地评估悬架承载梁的疲劳寿命,研究了焊接结构的疲劳测试与分析方法,提出了与CAE相结合的载荷谱测点合理布置原则。基于应变测试技术,合理布置测点,采集承载梁关键点的道路载荷谱,将三向应变花的载荷数据合成和获取动态signed VonMises应力;基于焊接结构的等级划分理论,研究了焊接结构性能相关的参数构成,最终确定了悬架承载梁结构的S-N曲线;基于雨流计数方法和损伤累计理论,实现了疲劳寿命的预估,获取了实车室内可靠性试验中悬架承载梁的考核结果;基于损伤评价理论进行了与室内可靠性试验结果的对比,形成了一套完整的基于实测载荷谱数据的焊接结构疲劳分析方法。研究结果表明,该疲劳分析方法和流程能够有效预测焊接结构的疲劳寿命。

In order to evaluate the fatigue life of the suspension bearing beam,fatigue testing and analysis methods for welded structures are studied.Combined with CAE,the principle of load spectrum point placement is put forward.Based on the strain testing technology,the road load spectrum of the key points of the bearing beam is collected to obtain the dynamic stress.Dynamic signed VonMises stress is synthetised from strain rosette data.The SN curve of the suspension bearing beam structure is determined based on the theory of welded structure classification.The parameters related to welding structure performance are studied.And the fatigue life prediction is finished based on the theory of rain flow counting and damage accumulation.Compared with the reliability test result in laboratory,the result is good.A complete set of fatigue analysis method for welded structures based on measured load spectrum data is formed.It is proved that the fatigue analysis method and process can effectively predict the fatigue life of welded structures.