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采用建筑钢材建造的工程结构,在其服役期内将不可避免地产生一些损伤,从而影响结构的内力分布规律,导致其部分应力可能超限,引起局部失效,严重者将使整个结构倒塌.为了直接测试这类结构的应力状态,从而确保这类结构的安全性,提出了钢材等铁磁材料基于磁力耦合效应的全磁通应力磁性无损检测法,即通过测试材料的全磁通量来测试材料的应力状态.根据铁磁材料磁特性的应力敏感这一特性,以圆形铁磁试件为研究对象,采用能量最小理论,推导了圆形铁磁试件磁感应强度同拉应力之间的相关关系方程,建立了其磁通量增量与拉应力关系的磁力学模型.该磁力学模型表明,铁磁试件在外加磁场和外加应力的共同作用下,其磁通量的变化量随拉应力的增大而增大,且与外加应力呈现出线性关系.所提磁力本构模型可为全磁通直力检测技术奠定基础,具有较好的理论意义和实用价值.“,”Those engineering structures built of steel will inevitably experience some damages during their service lifetime, which will influence the regularity of internal forces distribution in structures, result in over-limit stresses, cause local failure of structures, and even lead to collapse of whole structure. In order to ensure the safety of those structures, the nondestructive testing (NDT) of stress with the total magnetic flux is put forward for such ferromagnetic materials as steel. In this study, according to the stress sensitive characteristic of magnetic property of ferromagnetic material and the theory of micromagnetic energy, the dependency equation of the magnetic induction intensity versus stress is reasonably derived, and the magnetomechanical model between the incremental magnetic flux and stress is also established. From the model, when the ferromagnetic specimen subjected to the concurrent actions of applied fields and loads, the increment of magnetic flux increases with the tensile stresses, and exhibits a linearity to the external stresses. This model presented can form a fundamental basis for magnetic nondestructive stress testing of ferromagnetic material and will find great significance in theory and enjoy its wide application in engineering.