摘要
In order to propel the development of metal magnetic memory(MMM) technique in fatigue damage detection,the Jiles-Atherton model(J-A model) was modified to describe MMM mechanism in elastic stress stage.A series of rotating bending fatigue experiments were conducted to study the stress-magnetization relationship and verify the correctness of modified J-A model.In MMM detection,the magnetization of material irreversibly approaches to the local equilibrium state M0 instead of global equilibrium state Man under cyclic stress,and the M0-σ curves are loops around the Man-σ curve.The modified J-A model is constructed by replacing Man in J-A model with M0,and it can describe the magnetomechanical effect well at low external magnetic field.In the rotating bending fatigue experiments,the MMM field distribution in normal direction around cylinder specimen is similar to the stress distribution,and the calculation result of model coincides with experiment result after some necessary modifications.The MMM field variation with time at a certain point in fatigue process is divided into three stages with the variation of stable stress-stain hysteresis loop,and the calculation results of model can explain not only the three stages of MMM field changes,but also the different change laws when the applied magnetic field and initial magnetic field are different.The MMM field distribution in normal direction along specimen axis reflects stress concentration effect at artificial defect,and the magnetic signal fluctuates around the defect at late fatigue stage.The calculation results coincide with the initial MMM principle and can explain signal fluctuates around the defect.The modified J-A model can explain experiment results well,and it is fit for MMM field characterization.
In order to propel the development of metal magnetic memory (MMM) technique in fatigue damage detection, the Jiles-Atherton model (J-A model) was modified to describe MMM mechanism in elastic stress stage. A series of rotating bending fatigue experiments were conducted to study the stress-magnetization relationship and verify the correctness of modified J-A model. In MMM detection, the magnetization of material irreversibly approaches to the local equilibrium state Mo instead of global equilibrium state M^n under cyclic stress, and the M0-a curves are loops around the Mar,-a curve. The modified J-A model is constructed by replacing M~ in J-A model with M0, and it can describe the magnetomechanical effect well at low external magnetic field. In the rotating bending fatigue experiments, the MMM field distribution in normal direction around cylinder specimen is similar to the stress distribution, and the calculation result of model coincides with experiment result after some necessary modifications. The MMM field variation with time at a certain point in fatigue process is divided into three stages with the variation of stable stress-stain hysteresis loop, and the calculation results of model can explain not only the three stages of MMM field changes, but also the different change laws when the applied magnetic field and initial magnetic field are different. The MMM field distribution in normal direction along specimen axis reflects stress concentration effect at artificial defect, and the magnetic signal fluctuates around the defect at late fatigue stage. The calculation results coincide with the initial MMM principle and can explain signal fluctuates around the defect. The modified J-A model can explain experiment results well, and it is fit for MMM field characterization.
基金
Projects(11072056, 10772061) supported by the National Natural Science Foundation of China
Project(A200907) supported by the Natural Science Foundation of Heilongjiang Province,China
Project(20092322120001) supported by the PhD Programs Foundations of Ministry of Education of China
关键词
设计模型
金属磁记忆
疲劳损坏
表征
阿瑟
弯曲疲劳试验
早期
改性
metal magnetic memory
Jiles-Atherton model
rotating bending fatigue
magnetomechanical effect
local equilibriumstate