非比例载荷下考虑加载路径的多轴疲劳寿命预测模型  

Multiaxial fatigue life prediction model considering loadingpath under non-proportional loading

作　　者：高建雄 程琴 朱鹏年 GAO Jian−xiong;CHENG Qin;ZHU Peng−nian(School of Mechanical Engineering,Xinjiang University,Urumqi 830046,China)

机构地区：[1]新疆大学机械工程学院,乌鲁木齐830046

出　　处：《船舶力学》2025年第3期474-485,共12页Journal of Ship Mechanics

基　　金：国家自然科学基金资助项目(52065062);新疆维吾尔自治区高校基本科研业务费科研项目(XJEDU2023P007);新疆维吾尔自治区重点研发计划(2021B01003)。

摘　　要：循环加载下路径的非比例性所引起的附加强化效应,是造成材料疲劳寿命缩短的重要因素。针对这一问题,首先基于等效应变模型和临界面理论,以最大剪切应变幅所在平面为临界平面,综合考虑材料本身的非比例系数和加载路径的非比例性,引入一种新型非比例因子来量化非比例加载对于材料疲劳寿命的影响。其次,为考虑试件的损伤机理与疲劳破坏模式,以临界平面上的最大法向应力来表征其对疲劳破坏的贡献,在此基础上结合非比例因子,提出一种多轴疲劳寿命预测模型。最后,利用多轴载荷作用下四种材料的疲劳实验数据验证所提模型的有效性,并将预测结果与五种现有模型进行对比。研究结果表明:与现有模型相比,所提模型能够有效提升非比例载荷作用下多轴疲劳寿命的预测精度。The additional strengthening effect caused by the non-proportionality of loading-path under cyclic loading is an important factor that shortens fatigue life of material.To solve this issue,the plane of maximum shear strain amplitude was treated as the critical plane,and the non-proportionality of material and loading-path were both considered.A new non-proportionality factor was introduced to quantify the impact of non-proportionality loading on fatigue life of material based on the equivalent strain model and critical interface theory.Secondly,the damage mechanism and fatigue failure mode of the specimen were also considered,the maximum normal stress on the critical plane was adopted to characterize its contribution to fatigue failure.On this basis,a multiaxial fatigue life prediction model was proposed by combining the non-proportional factors.Finally,the proposed model was verified by using the fatigue test data of four materials under multiaxial loading,and the prediction results were compared with five proposed models.The results show that the proposed model can effectively improve the fatigue life prediction accuracy under non-proportional loads compared with the existing models.

关 键 词：非比例载荷 加载路径 多轴疲劳 寿命预测 临界平面 

分 类 号：TH114[机械工程—机械设计及理论]