中国机械工程
中國機械工程
중국궤계공정
CHINA MECHANICAl ENGINEERING
2014年
20期
2806-2809,2810
,共5页
铝合金%电阻点焊%疲劳性能%疲劳参量
鋁閤金%電阻點銲%疲勞性能%疲勞參量
려합금%전조점한%피로성능%피로삼량
aluminum alloy%resistance spot welding%fatigue performance%fatigue parameter
研究了铝合金A A 5754点焊拉剪接头的疲劳性能,获得了不同厚度试件的载荷寿命曲线。研究了铝合金焊点的疲劳失效模式,讨论了焊点疲劳裂纹的扩展形式,并测量了裂纹扩展路径与点焊熔核界面之间的角度。分析了点焊拉剪试件在同时承受I型和II型载荷时,疲劳裂纹的扩展方向,并与测量值进行了比较。利用疲劳破坏后沿铝板厚度方向的实际裂纹长度修正了裂纹尖端的局部应力强度因子,提出了评价焊点寿命的疲劳参量 K (i),并对试验数据进行了分析比较。结果证明 K (i)可以有效关联试件尺寸效应和焊点疲劳寿命,能够用于预测焊点疲劳寿命。
研究瞭鋁閤金A A 5754點銲拉剪接頭的疲勞性能,穫得瞭不同厚度試件的載荷壽命麯線。研究瞭鋁閤金銲點的疲勞失效模式,討論瞭銲點疲勞裂紋的擴展形式,併測量瞭裂紋擴展路徑與點銲鎔覈界麵之間的角度。分析瞭點銲拉剪試件在同時承受I型和II型載荷時,疲勞裂紋的擴展方嚮,併與測量值進行瞭比較。利用疲勞破壞後沿鋁闆厚度方嚮的實際裂紋長度脩正瞭裂紋尖耑的跼部應力彊度因子,提齣瞭評價銲點壽命的疲勞參量 K (i),併對試驗數據進行瞭分析比較。結果證明 K (i)可以有效關聯試件呎吋效應和銲點疲勞壽命,能夠用于預測銲點疲勞壽命。
연구료려합금A A 5754점한랍전접두적피로성능,획득료불동후도시건적재하수명곡선。연구료려합금한점적피로실효모식,토론료한점피로렬문적확전형식,병측량료렬문확전로경여점한용핵계면지간적각도。분석료점한랍전시건재동시승수I형화II형재하시,피로렬문적확전방향,병여측량치진행료비교。이용피로파배후연려판후도방향적실제렬문장도수정료렬문첨단적국부응력강도인자,제출료평개한점수명적피로삼량 K (i),병대시험수거진행료분석비교。결과증명 K (i)가이유효관련시건척촌효응화한점피로수명,능구용우예측한점피로수명。
Fatigue performance of spot welds of aluminum alloy AA5754 was investigated experi-mentally herein .Fatigue failure mode of spot welded tensile shear specimen was discussed and fatigue crack growth path was also explored .Theoretical crack growth angle was determined for tensile shear specimen ,which was under mix mode I/II loading ,and results were verified by measured angles of failed specimens .Local stress intensity factor at nugget circumference was derived ,modified by actual fatigue crack length in sheet thickness and treated as a fatigue parameter K(i) in fatigue data correla-tion .The proposed fatigue delete parameter is proven efficient in correlating fatigue data and can be used for fatigue life prediction of aluminum resistance spot welds .