Quantitative Analyses of Magnetic Field Distributions for Buildings of Steel Structure

Steel structures in buildings is magnetized by external geomagnetic field, thus the magnetic fields around the buildings are changed. A line element is used to mesh the complicatedly distributed magnetic materials in buildings, and the magnetic moment method (MMM) is used to model the magnetization of architectural components, then the resulted dense matrix is compressed by multilevel adaptive cross approximation (MLACA). Thus, the magnetic field distributions due to the steel building are analyzed quantitatively. Through the numerical examples, we show that this technique provides a fast and accurate tool for modeling the magnetic field signature of steel building, and have highly practical values.