磁记忆检测中的力-磁关系及其实验观察

从微磁化基本理论出发,依据能量原理,建立了铁磁材料的能量状态方程;采用最小能量原理和拉格朗日乘数法得出了在外力作用下铁磁体内应力与磁化率改变量之间的线性关系式.进一步讨论了在应力方向改变时应力与相应方向磁化率改变量间的对应关系,证明在不同方向上二者之间的线性关系依然成立.根据变压器原理,设计出铁磁材料磁化率检测装置,以45#钢试件为例,测量了不同方向上应力与磁化率变化量间的对应关系,并与理论值做了比较.实验结果表明文中得出的应力-磁化率变化量表达式与实验测定结果符合得较好.以上工作为明确磁记忆检测技术的检测对象和机理,建立磁记忆检测技术的力-磁本构关系在一个新的视角上做了有意义的探索.

Stress-magneto Relationship in Magnetic Memory Testing and Experimental Observation

Energy-state equation of ferromagnetic materials was established based on both micro magnetic theory and energy principle; a near-linear mathematical expression between the susceptibility change and the stress of ferromagnet under external forces was derived by using Lagrange multiplier method as well as minimum energy principle. Furthermore, a corresponding relation between stress orientation change and susceptibility change was discussed. It is proved that the derived near-linear expression is still suitable in different orientation. Based on transformer principle, a susceptibility detecting device was designed. Taking 45 # steel plate as testing specimen, corresponding relationship between susceptibility change in different orientations and stress were measured. The measured results and theoretical values were compared. Results show that the theoretical value derived from near-linearly stress-susceptibility change expression is well accorded with the measured results. This work is a meaningful exploration,from a angle of view,both for specifying the sampling object and testing mechanism and establishing mechanic-magneto consitutive relationship of metal magnetic memory testing technique.