一种多轴向耦合随机激励下缺口试件振动疲劳寿命预测方法  

A method for predicting vibration fatigue life of notched specimens under multi-axial coupled random excitation

作　　者：骆政波 范鑫 刘峰 陈怀海[2] 郑荣慧[2] LUO Zhengbo;FAN Xin;LIU Feng;CHEN Huaihai;ZHENG Ronghui(Anhui Provincial Engineering Lab of Aeronautical Equipment Measurement,Control and Reverse Engineering,State-owned Wuhu Machinery Factory,Wuhu 241007,China;State Key Lab for Structural Mechanics and Control of Machineries,School of Aeronautical Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China)

机构地区：[1]国营芜湖机械厂安徽省航空设备测控与逆向工程实验室,安徽芜湖241007 [2]南京航空航天大学航空学院机械结构力学及控制国家重点实验室,南京210016

出　　处：《振动与冲击》2023年第17期105-113,共9页Journal of Vibration and Shock

摘　　要：提出了一种多轴向耦合随机激励下缺口结构振动疲劳寿命预测的频域分析方法。实施了缺口试件的双轴向随机振动疲劳试验,研究了两个振动轴向上载荷谱之间的相干性和相位差对缺口试件疲劳损伤的影响规律;通过随机振动分析计算得到试件缺口根部各节点的应力功率谱密度矩阵,并假设缺口试件裂纹萌生点为历经von Mises应力最大均方根值的节点;缺口试件疲劳临界点可由疲劳裂纹初始点和修正临界距离理论确定;在疲劳临界点处通过Carpinteri-Spagnoli频域准则计算缺口试件的振动疲劳寿命,并与试验结果进行了对比。结果表明:该多轴缺口疲劳预测方法具有较高的预测精度,绝大部分预测结果都在3倍误差带内。Here,a frequency domain analysis method for predicting vibration fatigue life of notched structures under multi-axial coupled random excitation was proposed.Firstly,biaxial random vibration fatigue tests of notched specimens were conducted and effects of the coherence and phase difference between the two vibration axial load spectra on fatigue damage of notched specimens were studied.Then,the stress power spectral density matrix of each node at notch root of specimen was obtained through random vibration analysis and calculation,and it was assumed that the crack initiation point of notched specimen is the node with the maximum RMS value of ergodic von Mises stress.Subsequently,the fatigue critical point of notched specimen could be determined with the fatigue crack initial point and the corrected critical distance theory.Finally,the vibration fatigue life of notched specimen was calculated using Carpinteri-Spagnoli frequency domain criterion at the critical fatigue point and compared with test results.The results showed that the proposed notched specimen vibration fatigue life prediction method under multi-axial coupled random excitation has higher prediction accuracy,and the majority of prediction results are within a 3-fold error band.

关 键 词：振动疲劳 多轴向随机基础激励 相干性 临界距离理论 Carpinteri-Spagnoli准则 

分 类 号：TH113[机械工程—机械设计及理论]