Locally Defined Electromagnetic Force Density Inside Materials

An object's shape may be deformed by a combination of gravitational, hydrostatic, mechanical, and electromagnetic forces. Therefore, to predict the deformation, it is necessary to know each force's distribution inside the object. Various expressions and methods, such as the Lorentz, Kelvin, generalized, and Korteweg-Helmholtz forces, can be used to calculate the electromagnetic force on a dielectric or magnetic material. However, the distributions of the aforementioned forces inside materials may differ significantly. We adopt the concepts of infinitesimal particles and external electromagnetic fields to address this issue. Adopting these concepts enables the electromagnetic force densities inside dielectric or magnetic materials to be uniquely determined. We refer to this type of density as the locally defined electromagnetic force density (FLEM). This study primarily focuses on the derivation of F(LEM)• Subsequently, the distribution of FLEMis then demonstrated using simple numerical models.