摘要
针对车身使用的ST12低碳钢板,利用生产线上焊接设备制备了电阻点焊接头拉剪疲劳试件.对点焊接头区域进行了金相组织观测,测量了焊点附近的维氏硬度值分布.在MTS材料疲劳试验机上进行了恒幅疲劳加载,得到了ST12低碳钢板的电阻点焊接头的S-N曲线.基于所得的S-N曲线进行了两级疲劳加载试验,对两级加载下的线性累积疲劳损伤进行了分析.累积损伤结果分析表明,ST12低碳钢板电阻点焊件在两级加载下存在加载次序效应,高—低加载次序下加载次序效应更为明显.
Fatigue specimens were made of ST12 steel sheets with product line welding equipment.Microstructure in different zones was observed and Vicker's hardness around the weld nugget was measured.Constant amplitude fatigue loading was applied on specimens with MTS material testing frame to obtain the S-N curve.According to the constant amplitude fatigue test results,two-stage loading tests were carried out,and then linear damage accumulation rule was used for damage analysis under two-stage loading.Damage accumulation results show that there was loading sequence effect for low carbon ST12 steel spot welded joint under two-stage loading,the loading sequence effect under high-low loading sequence was even more explicit.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
2014年第6期35-38,114,共6页
Transactions of The China Welding Institution
基金
国家自然科学基金资助项目(51065012)
高等学校博士学科点专项科研基金资助课题(20105314120013)
昆明理工大学分析测试基金资助项目(2010313)
关键词
点焊接头
疲劳寿命
两级加载
加载次序
spot weld
fatigue life
two-stage loading
loading sequence
