Finite element analysis of high field permanent magnet mechanism using vector Preisach hysteresis model
This paper presents a method to simulate abnormal magnetizations in high field permanent magnet mechanism. Abnormal magnetizations including local saturation, local demagnetization and rotational magnetization occur in the assembly process of high field permanent magnet mechanism. Combining an anisotropic vector Preisach model and finite element analysis, abnormal magnetizations are simulated comprehensively. The method only requires the data of limiting magnetic hysteresis loops of the material along easy and hard axis, so the application of vector Preisach model becomes convenient and efficient. A sixteen elements enhanced magic ring is designed and the process of assembling is simulated, which verify the validity of the presented method.
A simplified vector Preisach model
Although scalar Preisach models have been increasingly accurate and efficient in describing material behavior, vector models, necessary to quantize complex magnetizing processes, are not as well developed. This paper presents a coupled vector model where the coupling is performed by a set of selection rules, after which the individual components can be calculated independently, This model reduces to a scalar model under appropriate conditions and the identification of its parameters is very straightforward.
Energy considerations in hysteresis models
The energy dissipated by a magnetic material is computed for both a single particle and an assembly of particles represented by a generalized Preisach model. For an isolated particle, the two components of the energy loss are due to sudden change in the irreversible magnetization and due to the change in the ability of the magnetization to store energy because of the change in state. The former loss is equal to the product of the permeability, the applied field, and the discontinuous magnetization change. It is noted that the size of the discontinuous change in magnetization is generally not equal to the difference of the two remanent magnetizations. These energy loss components carry over into the computation for an assembly of particles. >