摘要
准确地估计疲劳寿命对于汽车零部件的可靠性和轻量化设计具有重要的作用。但由于现有疲劳寿命估计方法认为载荷仅对零件造成损伤,导致工作载荷下基于传统疲劳寿命预估方法得到的疲劳寿命较为保守。大量研究结果表明,疲劳极限以下载荷对零件疲劳强度的强化作用。以碳钢低载强化特性为基础,基于Miner准则,提出一种考虑低载强化效果的简化的疲劳寿命预估方法。该方法将疲劳寿命预估分成两个阶段,在不同的阶段分别考虑低幅载荷的强化和损伤。通过对强化效果与强化载荷和强化次数的关系进行线性简化,简化了疲劳寿命的计算过程。以轿车扭杆梁后桥为对象,通过采集试车场道路下的工作载荷,利用该方法和Miner准则对后桥进行疲劳寿命估计,并通过道路载荷模拟技术对后桥进行试验验证。结果表明,该方法具有较高的精度。
Accurately estimating the fatigue life is critical to reliability and lightweight design of automobile parts. But the lives predicted based on existing methods under service loading histories are usually conservative, for which considers load will only cause damage. However, researches show that specific loads under fatigue limit are of strengthening effect on fatigue strength. Therefore, a fatigue life prediction method which takes into account the strengthening effect of loads below fatigue limit is proposed based on Miner＇s rule. In this method, the process of fatigue life prediction is divided into two parts, and the damaging and strengthening effect of loads below fatigue limit are considered separately. And the relationship between strengthening effect and strengthening load and their reversals are simplified by linearization. Taking rear axle of automobile as an example, fatigue life is predicted by this new method and traditional Miner＇s rule. Comparing with the lives of fatigue tests on road load simulator, results show that this new method is of higher accuracy.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2013年第8期115-122,共8页
Journal of Mechanical Engineering
基金
国家高技术研究发展计划(863计划
2011AA11A265)
国家自然科学基金(50875173)
上海市科委科研计划(11140502000)
上海市科委基础研究重点(10JC1411600)
上海汽车工业科技发展基金(1104)资助项目
关键词
低载强化
寿命估计
疲劳寿命
疲劳强度
Fatigue life Low-amplitude-load strengthening Fatigue strength Load spectrum Rear axle
