摘要
针对等效应变模型在多轴非比例加载时不能考虑到材料的附加强化作用,而造成疲劳寿命预测误差较大的缺陷,基于临界面理论,将最大剪切应变幅作为主要的疲劳损伤参量。同时,将相位差、最大法向应力和剪切应力组成一个附加损伤系数作为次要损伤参量,来反映金属材料在多轴非比例加载下产生的附加强化效应;损伤系数中最大剪切面上的剪切应力对最大法向应力进行归一化处理来反映两个应力相互作用对疲劳寿命的影响。提出的模型在不引入额外的经验拟合常数的情形下,不仅保留了等效应变模型参数的所有优点,还有助于发现裂纹产生的机制和反映裂纹延伸方向。采用6种均为薄壁圆管的金属材料数据对提出的模型和3种经典模型进行数据验证,对比分析后的结果显示,提出的模型相对另外3种模型,得到的预测结果精确度更高且数据分布更稳定。
For the equivalent strain model,the additional strengthening effect of the material cannot be considered during multiaxial non-proportional loading,resulting in a defect with a large error in fatigue life prediction,based on the pro-interface theory,the maximum shear strain amplitude was used as the main fatigue damage parameter.At the same time,the phase difference,maximum normal stress and shear stress were composed of an additional damage coefficient as a secondary damage parameter to reflect the additional strengthening effect of the metal material under multiaxial non-proportional loading,and the shear stress on the maximum shear surface in the damage coefficient normalized the maximum normal stress to reflect the influence of the interaction between the two stresses on the fatigue life.The proposed model not only retains all the advantages of the equivalent model parameters without introducing additional empirical fitting constants,but also helps to discover the mechanism of crack generation and reflect the direction of crack elongation.The proposed model and three classical models were verified by using six kinds of metal material data of thin-walled round tubes,after analyzing the data verification results of each model,it is found that the prediction results of the proposed model have higher accuracy and more stable data distribution.
作者
程琴
高建雄
袁逸萍
刘媛媛
杨浩进
衡飞
CHENG Qin;GAO JianXiong;YUAN YiPing;LIU YuanYuan;YANG HaoJin;HENG Fei(School of Mechanical Engineering,Xinjiang University,Urumqi 830017,China)
出处
《机械强度》
CAS
CSCD
北大核心
2024年第5期1200-1206,共7页
Journal of Mechanical Strength
基金
国家自然科学基金项目(52065062)
新疆维吾尔自治区重点研发项目(2021B01003)
新疆维吾尔自治区自然科学基金项目(2020D01C056)资助。
关键词
多轴疲劳
等效应变
非比例附加强化
剪切力
相位差
Multiaxial fatigue
Equivalent strain
Non-proportional additional reinforcement
Shear force
Phase difference
