Study of Computation Method of Iron Loss Considering Magnetic Isotropic by Processing Residual Stress

Abstract

Mass productions of the motor core such as the blanking of the electromagnetic steel sheet and the shrink fit cause the residual strain in the material, processing strain, which prevents the movement of magnetic walls and increases the magnetic loss in the motor. Conventionally, the increase of the magnetic loss by the processing stress was evaluated with trial products, because it couldn't be done in the design phase. Particularly, the residual stress generated by processing has a complicated relationship with the direction of the magnetization vector, which has made it difficult to estimate iron loss considering processing strain.

So this paper clarified the relationship between the stress tensor and the magnetization vector, and proposed a consideration method of the stress in magnetic field analysis. As a result of validating the development method with the ring test piece, we confirmed that the intended modeling can be reproduced. Furthermore, we showed the usefulness of the development method in the motor model.