Electromagnetic Simulation of Low-Frequency Magnetic Shielding of a Welded Steel Plate

In this article, we experimentally evaluated the effectiveness of magnetic shielding for welded steel plates with the control of parameters such as a gap and a spot spacing for automobiles at frequencies below 1000 kHz, and predicted the shielding effectiveness by an electromagnetic analysis. It is shown that the shielding effectiveness of welded steel plates is reduced by more than 20 dB compared to that of a single plate above 10 kHz. Moreover, the shielding effectiveness of the welded steel plates strongly depended on the spacing between the spot welds, and the mechanism was studied by analyzing the eddy currents in the plates. These results provide important data for automotive design to reduce human exposure to electromagnetic waves.