The goal of the study was to evaluate a relative decrease in magnetic permeability in open magnetic circuits based on stray magnetic field measurements. The boundary element method was used to simulate magnetic circuits with variable geometry and variable magnetic permeability. The simulated magnetic circuits were rectangular or bone-shaped flat samples. Reluctance was increased in the middle of the samples resulting in leakage of magnetic flux. An analysis was performed to determine relations between the leakage and factors that increase the reluctance of the samples. These factors were the cross-sectional area and magnetic permeability. In case of strong demagnetization of a ferromagnetic sample, an approach to quantitative evaluation of a stray magnetic field distribution was proposed. Results of the analysis indicate that the amplitude of the tangential component of the stray magnetic field increases with the increasing absolute value of the relative change of the reluctance. The same tendency was observed in the case of the gradient of the normal component. The decrease in the cross-sectional area of the sample (and more precisely its width) has similar influence on the stray magnetic field as the decrease in the magnetic permeability. These two factors were also studied in the coincidence and the possibility of isolation of information about a relative decrease in the magnetic permeability was verified. The isolation scheme was formulated and validated based on experimental as well as numerical data. Results of the validation indicate that it is possible to make a rough estimation of a local reduction in the magnetic permeability based on stray field measurements.
Authors
Additional information
- Category
- Aktywność konferencyjna
- Type
- publikacja w wydawnictwie zbiorowym recenzowanym (także w materiałach konferencyjnych)
- Language
- angielski
- Publication year
- 2018
