某商用车车架台架疲劳寿命预测与提升.pdfVIP

第 5 期 机械设计与制造 2018 年 5 月 Machinery Design ＆ Manufacture 117 某商用车车架台架疲劳寿命预测与提升 王树英，陈有松，石文山，韩红阳 （上海汽车集团股份有限公司商用车技术中心） 摘 要：新开发商用车车架进行扭转台架疲劳试验时，第三横梁与纵梁连接处焊缝开裂，不满足车架循环次数 20 万次寿 命要求；需要采用有限元法模拟车架扭转疲劳台架试验，以找出焊缝开裂原因并提出改进方案，比较不同焊缝建模方法计算 所得车架扭转台架疲劳寿命，确定与台架试验结果吻合的焊缝建模方法；对车架焊缝开裂风险位置进行结构优化设计，提升 纵梁横梁接头强度，先用有限元方法验证车架优化方案满足寿命要求后，再将优化后的车架进行台架试验，车架未发生开裂。 应用有限元方法预测台架疲劳耐久寿命，可以找出焊缝开裂原因并快速验证优化方案，缩短产品开发周期。 关键词：车架；台架试验；有限元建模；焊缝；疲劳寿命；优化设计 中图分类号：TH16 文献标识码：A 文章编号：1001-3997（2018）05-0117-03 Bench Test Fatigue Life Prediction and lmprovementof an Commercial Frame WANG Shu-ying ， CHEN You-song ， SHI Wen-shan ， HAN Hong-yang （SAIC Motor Commercial Vehicle Technical Center ， China ） Abstract ：During the fatigue torsion bench test of new -designed frame ， the seam weld between 3# cross beam and rail cracked. The new frame didnt meet the fatigue life requirement of 200000 repeat cycles. To find the root cause of the failure and to propose improvement for frame ， a FEM model of frame shall be developed to analyze bench test. Two different modeling methods of seam weld were compared and the better one was determined ， Improvement was proposed by increasing the strength of connection between 3# cross beam and rail. The modified frame fatigue life was validated based on FEM method firstly. Bench tests then was carried on the modified frame. There is no crack occurred during the required fatigue life period. The root cause of crack and improvemen t can be quickly found by using FEM method ， which can save time and money during product development process. Key Words ：Frame ；Bench Test ；Fem Model ；