轿车后副车架多轴疲劳分析

摘要

以某轿车五连杆独立后悬架的副车架为研究对象,根据台架试验方法建立了后悬架系统有限元模型,利用虚拟应变片技术和焊缝寿命预测技术,通过CAE分析与台架试验测试相结合,通过改进结构降低裂纹位置的疲劳损伤值,解决了该后副车架在台架试验中焊接位置出现裂纹的问题.改进结构一次性通过了8通道耐久性台架试验,表明有限元分析与台架试验相结合的方法可有效预测副车架焊缝疲劳寿命.%With a car with five-link independent rear suspension as study object,a rear suspension FE model was established according to the test method in this paper.Virtual strain gauge technology and welding seam life predication technology were used to prevent cracking at the welding position of rear sub-frame in bench test by improving structure to reduce fatigue damage value at the cracking position,through CAE analysis and bench test.The optimized sub-frame passed the 8-tunnel durability bench test successfully at one time,indicating that the method which combines FEA and bench test can effectively predicate fatigue life of sub-frame welding seam.