Analysis of structural deformation and vibration of a transformer core by using magnetic property of magnetostriction

A technique for structural analysis of transformer cores in terms of magnetostriction is proposed. The magnetic flux density of each element is first calculated by the finite element method (FEM). Then the magnetostrictive force on each element is calculated from measurements. The magnetostriction is specified as the initial strain and is converted into the force on each node, and a structural analysis is performed. The advantage of specifying the magnetostriction as the initial strain is that it is possible to obtain the force at the location of each element as a vector. Modal analysis and frequency response analysis were also performed and it was shown that resonance is related to the magnetostrictive frequency and the natural mode. Thus, it becomes possible to forecast the frequency at which the core vibrates most strongly which makes the proposed technique of analysis is very useful.