Optimized Analysis Model and Improvement Method for the Performance of Magnetic Shielding Device Considering Stress Effects

High-performance magnetic shielding device provides a near-zero magnetic field (mf) environment for mf measurement. In the installation process of the magnetic shielding device, the permalloy layer usually adopts a splicing configuration and is fixed by bakelite plates. Since the characteristic of the permalloy is extremely sensitive to stress, the stress introduced by the pressure plate will reduce the actual shielding performance. In order to accurately assess the residual mf of magnetic shielding devices, it is necessary to establish an analysis model considering the influence of stress. However, there have been a few studies addressing this issue. In this article, the optimized analysis model considering force-magnetic coupling is established, and the real-time correction analysis of shielding performance under different stresses is realized. When the bolt torque of the pressure plate is 12 N.m, if the influence of stress is not considered, the error between the analysis result and the measurement result is 88.2%, and the error is reduced to about 6% after the model considering stress is applied. The model considering the stress improves the calculation accuracy of the residual mf of the magnetic shielding device, which is of great significance for the design and application of the magnetic shielding device.