一种考虑平均应力影响的疲劳寿命预测方法  

A fatigue life prediction method considering influence of mean stress

作　　者：李静[1] 刘豪 华腾飞 仇原鹰[1] LI Jing;LIU Hao;HUA Tengfei;QIU Yuanying(School of Mechatronic Engineering,Xidian University,Xi’an 710071,China)

机构地区：[1]西安电子科技大学机电工程学院,陕西西安710071

出　　处：《华中科技大学学报(自然科学版)》2024年第12期70-76,共7页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：陕西省自然科学基础研究计划资助项目(2023-JC-YB-328);中央高校基本科研业务费专项资金资助项目(ZYTS23014)。

摘　　要：为了更好地预测材料的多轴疲劳寿命,在利用疲劳寿命缩减因子和非比例度因子修正的美国机械工程师学会(ASME)等效应变模型的基础上,基于临界平面理论并结合Smith-Watson-Topper(SWT)平均应力修正方法,构建了一个可以考虑平均应力影响的多轴疲劳寿命预测模型.新模型通过引入权重系数来反映拉伸平均应力和压缩平均应力对疲劳寿命影响的不同,利用7075-T651铝合金、Ti-4Al-6V钛合金和S460N钢等3种材料在18种加载路径(包括11种对称循环加载和7种非对称循环加载)下的256组疲劳试验数据,对新建模型的预测能力进行了验证.结果表明:无论单轴加载还是多轴加载,也无论对称循环加载还是非对称循环加载,新模型都具有较好的预测精度,95.3%的试验点位于3倍误差带以内.The American Society of Mechanical Engineers(ASME)-based equivalent strain model corrected by fatigue life reduction factor and non-proportionality factor was improved further by combining the Smith-Watson-Topper(SWT)mean stress correction method,a multi-axis fatigue life prediction model that takes into account the influence of mean stress was constructed.In this new developed model,a weight factor was introduced to reflect the different influence of tensile mean stress and compressive mean stress on fatigue life.The predictability of the proposed model was validated by using 256 fatigue datasets of 7075-T651 aluminum alloy,Ti-4Al-6V titanium alloy,and S460N steel that are tested under 18 kinds of loading paths(including 11 symmetric cyclic loadings and 7 asymmetric cyclic loadings).Results show that the proposed model has satisfactory prediction accuracy regardless of whether there is non-zero mean stress in the loading paths,and most of the data points fall within factor-of-three boundary.

关 键 词：多轴疲劳 平均应力 寿命预测 权重系数 非对称循环加载 

分 类 号：O346.2[理学—固体力学]