The magneto-mechanical effect combines the magnetic field and stress σ, making it an important approach for detecting stress concentration and microscopic failure in electrical machines. Alloy sheets as Fe-Si3% used in mechanical structures are subject to the effect of both magnetic and mechanical constraints, but the effects of a mechanical stress on this type of alloy are not widely considered. In previous work, a theoretical approach was proposed, which was obtained by incorporating, in the classical effective field model given by Jiles-Atherton (JA), the effect of an equivalent stress demagnetizing field denoted H_dϭ. Presence of this parameter explains the asymmetry in the change of magnetization under the conditions of tensile and compressive stress. Stress concentration affects all properties of the material. The intermolecular interaction inside the sheet defined by the classical domain coupling factor α is one of more parameters which is affected and need to be modeled. This paper proposes to elaborate a new model based on the merits of the previous approach. An accurate model denoted α_eff is thus developed. The evolution of α_eff and the magnetostrictive behaviors are simulated at an average frequency f = 50 Hz under tensile stresses. The obtained results are compared with some reported ones; the tendency is shown to be in concordance with those published.