振动环境下焊缝疲劳寿命的预测及分析  

Forecast and Analysis of the Weld Fatigue Life Under Vibration Environment

作　　者：张凤[1] 李健[1] 李鹤[1] 

机构地区：[1]东北大学机械工程与自动化学院,辽宁沈阳110819

出　　处：《机械设计与制造》2014年第11期228-231,共4页Machinery Design & Manufacture

基　　金：教育部基本科研业务费项目(N120203001;N130803001)

摘　　要：根据名义应力法,对某结构焊缝在振动环境下的疲劳寿命进行了预测,并对影响焊缝疲劳寿命的因素进行了分析。使用振动台模拟真实振动工况环境,并得到对接焊缝不同焊点在此模拟振动环境下的应力—时间曲线。首先,应用雨流计数法得到各级应力的循环次数;然后,以BS7608标准中提供的焊缝S-N曲线为依据求得各级应力下焊缝的疲劳寿命;最后,根据Miner线性累积损伤理论预测各焊点的疲劳寿命并分析影响焊缝疲劳寿命的主要因素。分析结果表明:焊缝的存在降低了构件的疲劳寿命,且焊缝焊点的位值及余高的存在影响了焊缝的疲劳寿命。此分析结果与工程实际中对接焊缝的断裂情况相吻合,证明了此焊缝疲劳寿命预测方法的正确性。Based on the nominal stress method, fatigue life of structure welds under a vibration environment are assessed and the factors which impact the fatigue life of the weld are analyzed. The real vibration environment is simulated by the vibration table and strain-time curves of different butt welded joints are obtained through experiment which in such simulated vibration environment. Firstly, the rain flow counting method is applied to get the number of cycles of each stress levels. Secondly, based on the S-N fatigue curves of weld which are provided by BS7608 standard, the weld life under each stress level is got. Lastly, according to the miner linear cumulative damage theory, the fatigue life of every joint is calculated and the factors which impact the fatigue life of the weld are analyzed. The results show that the presence of the weld reduces the fatigue life of the components and the location of the solder joints and the presence of the high portion have influence on the fatigue life of the weld. The results of this analysis coincide with the breakage of the butt welds in practice and it proves the correctness of this prediction method of weld fatigue life.

关 键 词：名义应力法 疲劳寿命 雨流计数法 BS7608标准 S-N曲线 线性累积损伤理论 

分 类 号：TH16[机械工程—机械制造及自动化] TH123.3