磁记忆信号的量化描述  

Quantitative representation of magnetic memory signal

作　　者：徐明秀[1] 尤天庆 徐敏强[3] 樊久铭[3] 李立[4] 

机构地区：[1]北京科技大学数理学院,北京100083 [2]北京宇航系统工程研究所,北京100076 [3]哈尔滨工业大学航天学院,黑龙江哈尔滨150001 [4]齐齐哈尔大学理学院,黑龙江齐齐哈尔161006

出　　处：《中南大学学报（自然科学版）》2015年第4期1215-1223,共9页Journal of Central South University:Science and Technology

基　　金：中央高校基本科研业务费专项资金资助项目(FRF-TP-14-067A2);国家自然科学基金资助项目(10772061);黑龙江省自然科学基金资助项目(A201210)~~

摘　　要：采用描述材料内部磁化强度的改进的J-A理论用于分析磁记忆现象,然而磁记忆信号反映材料的表面磁场,建立这两者之间的关系。首先,设计拉伸疲劳实验研究损伤区域的磁记忆信号分布及变化特征;然后,根据实验结果建立磁偶极子模型描述材料表面散射磁场;之后,通过改进的J-A理论建立散射磁场与材料内部磁化参量M0的关系,量化描述磁记忆信号。研究结果表明:条形损伤集中区域成为内部磁源,向外散射磁场;试件外某点的散射磁场由损伤集中区域的磁荷密度和尺寸、裂纹的磁荷密度、裂纹的尺寸和位置,以及该点所处的位置确定,并随磁荷密度及裂纹尺寸变化;损伤集中区域的磁荷密度与M0呈线性关系,裂纹的磁荷密度与M0呈线性关系、并与裂纹尺寸有关;磁偶极子模型描述的试件表面磁场的分布及分布变化特征符合实验测量结果,并可根据改进的J-A模型推得疲劳过程中磁记忆信号与应力、材料损伤情况、裂纹影响因子之间的量化关系式。The modified J-A model that describes the magnetization intensity inside the material was used in the metal magnetic memory（MMM） phenomenon analysis. However, the MMM signal reflected the magnetic field outside the material. The relationship between the magnetization intensity and the MMM signal outside the material was established.First, the tensile fatigue test was conducted to study the distribution and variation characters of the MMM signal outside the damage area. Then, according to the experimental results, a magnetic dipole model was constructed to describe the scattering magnetic field. After that, the scattering magnetic field was related to the magnetization parameter M0 in the modified J-A model, and the MMM signal was described quantitatively. The research results show that the bar-type damage concentration area becomes the interior magnetic source and scatter magnetic field outside; that the scattering magnetic field at a certain point outside the specimen is decided by the magnetic charge density and size of damage concentration area, the magnetic charge density of crack, the size and location of crack, and the location of this point; and that the scattering magnetic field varies with the magnetic charge density of damage concentration area, the magnetic charge density of crack, and the size of crack. The magnetic charge density of damage concentration area has a linear increase relation with M0, and the magnetic charge density of crack has a linear relation with M0 and relates with crack size. The distribution and distribution variation characters of magnetic field described by the magnetic dipole model are in accordance with the experimental results. And the quantitatively relational expression among the MMM signal,stress, material damage situation and crack impact factor is obtained based on the magnetic dipole model and the modified J-A model.

关 键 词：磁记忆 磁偶极子模型 散射磁场 J-A理论 疲劳损伤 量化描述 

分 类 号：O346.2[理学—固体力学] O441.2[理学—力学]