裂纹扩展过程中电磁谐振疲劳试验系统动态特性分析  

Dynamic Characteristics Analysis of Electromagnetic Resonance Fatigue Testing System during the Fatigue Crack Growing Process

作　　者：高红俐[1] 郑欢斌 朱亚伦 

机构地区：[1]浙江工业大学特种装备制造与先进加工技术教育部/浙江省重点实验室,杭州310014

出　　处：《机械工程学报》2016年第24期88-98,共11页Journal of Mechanical Engineering

摘　　要：电磁谐振疲劳裂纹扩展试验系统是一种工作在谐振状态下测试金属材料断裂特性的试验装置,要求在裂纹扩展过程中精确跟踪系统的固有频率和控制试验载荷,为达到这一目的,需要对裂纹扩展过程中系统的动态特性进行精确的分析。据此,建立3自由度有阻尼电磁谐振疲劳试验振动系统的数学模型,采用ANSYS有限元法计算CT紧凑拉伸试件的刚度,研究不同材料试件刚度、系统固有频率,试验载荷幅频曲线、共振振幅在裂纹扩展过程中的变化规律,并进行相关试验,试验结果表明:系统固有频率计算值与试验测量值之间的最大偏差为1.9 Hz;系统动态特性仿真结果与试验结果能够较好地吻合。该研究结果为电磁谐振式疲劳试验载荷的高精度控制提供了理论依据。The electromagnetic resonant fatigue crack propagation testing system is a device applied to test metal material fracture characteristics under the resonant condition, which is required to trace the system natural frequency and control the test load precisely during the fatigue crack growing process. So, it is necessary to analyze the system dynamic characteristics accurately during the fatigue crack propagation process. Accordingly, the electromagnetic resonant fatigue test vibration system model of three degree freedom with damping has been established, the stiffness of compact tension（CT） test specimen of different materials are calculated using finite element method, and the relation of CT specimen stiffness with crack propagation length has been obtained. The variation laws of system natural frequency, test load amplitude-frequency curve and resonance amplitude during the fatigue crack propagation process have been researched, and some related experiments also have been carried out. The experimental results show that the system natural frequency maximum deviation value between the theoretical and the experimental data is 1.9 Hz, and the system dynamic characteristics simulation results match well with the experimental results. Furthermore,the research results supply a theoretical foundation for the precise controll of electromagnetic resonant fatigue test load.

关 键 词：电磁谐振疲劳试验 疲劳裂纹扩展 多自由度振动系统 动态特性 有限元法 试验载荷 

分 类 号：TP394[自动化与计算机技术—计算机应用技术] TB534[自动化与计算机技术—计算机科学与技术]