两种形状汽车大梁板试样的轴向疲劳行为研究  

Axial Fatigue Behavior of Automobile Beam Plate Specimens with Two Kinds of Shapes

作　　者：苏洪英[1] 刘仁东[1] 吕冬[1] 林利[1] 丁庶炜[1] 张瑞坤 SU Hongying;LIU Rendong;LYU Dong;LIN Li;DING Shuwei;ZHANG Ruikun(Angang Steel Technology Center, Anshan Liaoning 114009, China)

机构地区：[1]鞍钢技术中心,辽宁鞍山114009

出　　处：《上海金属》2020年第4期34-39,共6页Shanghai Metals

摘　　要：以500L-Z汽车大梁板为研究对象,对漏斗形试样和等截面试样分别进行应力比(R)为-1和0.1以及高、低两个应力水平的轴向疲劳试验。介绍了采用母体标准差相同的成组对比试验的t检验法和母体标准差不同的成组对比试验的t′检验法,并用切割应力松弛法测试两种形状试样表面的残余应力,分析其产生疲劳性能差异的原因。结果表明:在95%置信度下,当R=-1时,在250和330 MPa应力水平下,漏斗形试样的疲劳寿命分别是等截面试样的2.22~5.76倍和2.01~2.44倍;当R=0.1时,在475和550 MPa应力水平下,漏斗形试样的疲劳寿命分别是等截面试样的2.04~3.14倍和1.80~2.74倍。漏斗形试样的疲劳性能明显优于等截面试样。由试样形状引起的应力集中和表面残余压应力差异是造成两种形状试样疲劳性能差异的主要原因。Taking automobile beam steel plate 500L-Z as the research object,the axial fatigue tests of funnel-shaped specimen and equal sectional specimen were carried out at stress ratio of-1 and 0.1 and at high and low stress levels,respectively.The t-test method of group comparison test in which standard deviation was the same and t′-test method of group comparison test in which standard deviation was different were introduced.The surface residual stress of two kinds of specimens was tested by cutting stress relaxation method,and the cause for the difference in fatigue performance was analyzed.The results showed that when the stress ratio was-1,the fatigue life of the funnel-shaped specimen was 2.22 to 5.76 times and 2.01 to 2.44 times that of the equal sectional specimen under the conditions of 250 MPa and 330 MPa stress levels and 95%confidence,respectively;and when the stress ratio was 0.1,the fatigue life of the funnel-shaped specimen was 2.04 to 3.14 times and 1.80 to 2.74 times that of the equal sectional specimen under the conditions of 475 MPa and 550 MPa stress levels and 95%confidence,respectively.The fatigue performance of funnel-shaped specimen was much better than that of equal sectional specimen due to difference in stress concentration and surface residual compressive stress caused by the specimen shape.

关 键 词：汽车大梁板 疲劳试验 疲劳寿命 漏斗形试样 等截面试样 

分 类 号：TG1[金属学及工艺—金属学]