摘要
针对非对称载荷作用下平均应力对结构的疲劳寿命有显著影响的特点,在Manson-Coffin模型及其既有改进模型基础上,引入屈服极限和强度极限应力之间的相对量度对疲劳强度系数σ_(f)′进行修正,以体现平均应力对疲劳寿命的非线性影响,从而建立了改进的Manson-Coffin模型.根据三种常用材料的疲劳试验数据,对前述改进模型的疲劳寿命预测有效性和可行性进行验证.结果表明:与传统Manson-Coffin模型和其既有改进模型相比,所建议的模型能够更好地体现平均应力对疲劳寿命的非线性影响,有效地提高了非对称载荷作用下低周疲劳寿命预测的精度,为实际工程中结构的疲劳寿命提供了有效的预测技术.
Considering the significant effects of mean stress on fatigue life of the structure under asymmetric load,the relative measurement between the yield and the strength limits was introduced to reflect the nonlinear effect of mean stress on fatigue life through modification of the fatigue strength coefficient based on Manson-Coffin model and its existing improved models.Thereby,an improved Manson-Coffin model was established.According to the fatigue test data of three commonly used materials,the validity and feasibility of fatigue life prediction in aforementioned improved model were verified.The results show that compared with the traditional Manson-Coffin model and its existing improved models,the model proposed in this study can better reflect the nonlinear effect of mean stress on fatigue life and effectively improve the accuracy of life prediction in low-cycle fatigue under asymmetric loads,which provides an effective prediction technology for the fatigue life of structures in actual engineering.
作者
蒋广龙
高月华
刘其鹏
JIANG Guanglong;GAO Yuehua;LIU Qipeng(School of Civil Engineering,Dalian Jiaotong University,Dalian 116028,China;College of Aviation Manufacturing Engineering,Nanchang Hangkong University,Nanchang 330063,China;School of Locomotive and Rolling Stock Engineering,Dalian Jiaotong University,Dalian 116028,China)
出处
《大连交通大学学报》
CAS
2022年第3期41-45,78,共6页
Journal of Dalian Jiaotong University
基金
国家自然科学基金资助项目(51875073)
辽宁省教育厅高等学校科学研究计划资助项目(JDL2019031)
辽宁省自然科学基金资助项目(20170540120)。
