为了研究铁磁性物质在屈服点前后的临界应力及金属磁记忆信号特性，基于密度泛函理论，从固体能带理论出发，建立了磁力学耦合模型，计算了应力作用下铁磁晶体的晶格结构、差分电荷密度等的变化情况，并在不同压力下设计了钢管打压试验。结果表明：随着应力的增加，晶体中原子结合力逐渐下降，晶格稳定性受到影响；当应力集中达到一定程度时，原子磁矩突然发生变化导致晶体内部发生相变，磁记忆信号产生突变。从试验的角度分析了屈服前后磁记忆信号的差异，证明了利用第一性原理方法研究铁磁材料磁力学关系的可行性。

In order to study the critical stress and metal magnetic memory signal characteristics of ferromagnetic materials before and after the yield point, based on the density functional theory, a magnetic coupling model was established based on the theory of solid energy band, and the crystal of ferromagnetic crystal under stress was calculated. The change of lattice structure, differential charge density, etc., and the steel pipe compression test were designed under different pressures. The results show that as the stress increases, the atomic bonding force in the crystal gradually decreases, which affects the lattice stability. When a certain degree of stress concentration is reached, the atomic magnetic moment suddenly changes to cause phase transformation inside the crystal and the abrupt changes of magnetic memory signal. The difference of magnetic memory signals before and after yielding is analyzed from the experimental point of view, and the feasibility of using the first principle method to study the magnetic mechanics relationship of ferromagnetic materials is proved.