基于LMTO算法磁记忆屈服信号的定量化分析

发布时间：2018-05-17 08:16

本文选题：磁记忆 + 屈服　；参考：《仪器仪表学报》2017年06期

【摘要】：磁记忆法对铁磁性金属构件的应力集中区域具有很好检测效果。但是,目前构件在弹性阶段和塑性阶段的磁记忆信号特征很难被区分,从而无法对构件的应力集中程度和使用寿命进行有效评估。基于固体电子理论建立了磁记忆效应的边界滑移模型,利用线性化M-T轨道算法(LMTO)计算了固体在弹性、塑性阶段,系统的能量变化、不同轨道电子的自旋态密度的变化情况,进而定量分析了构件发生屈服后的磁记忆信号变化规律。研究结果表明,应力集中程度与系统边界滑移能量呈线性正比例关系,与电子自旋态密度峰峰值、磁记忆信号呈线性反比例关系;构件发生塑性形变后,体系能量和电子自旋发生不可逆的变化,磁记忆信号曲线出现转折点;构件每发生一次塑性变形,磁记忆信号初始值都会变小,曲线斜率变小。
[Abstract]:Magnetic memory method has a good detection effect on the stress concentration area of ferromagnetic metal components. However, the characteristics of the magnetic memory signal in the elastic phase and the plastic stage are difficult to be distinguished, so that the stress concentration and the service life of the components can not be effectively evaluated. The boundary slip model, using the linearized M-T orbit algorithm (LMTO), is used to calculate the change of the spin state density of the solid in the elastic, plastic stage, the system energy change and the different orbital electrons. Then the change law of the magnetic memory signal after the yield has been analyzed. The results show that the degree of stress concentration and the boundary slip of the system are slipping. The energy shows a linear positive proportional relation with the peak peak of the electron spin state and the linear inverse relationship with the magnetic memory signal. After the plastic deformation of the component, the energy and electron spin of the system change irreversible, the magnetic memory signal curve has a turning point, and the initial value of the magnetic memory signal will be smaller, and the initial value of the magnetic memory signal will be smaller. The slope is smaller.
【作者单位】：沈阳工业大学信息科学与工程学院;
【基金】：国家重大科学专项(2012YQ090175) 国家自然科学基金(61571308) 辽宁省教育厅项目(L2015388)资助
【分类号】：TG115.284

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