Abstract
This paper deals with a large-scale 3D non-linear magnetostatic analysis using the Hierarchical Domain Decomposition Method (HDDM). To improve the convergence of the interface problem of the HDDM and to reduce the computation time, the solution strategy of Finite Element Analysis (FEA) in subdomains is reexamined. Because our employed equation is singular, it has been solved by the iterative method such as the ICCG method. However, by applying the direct method for solving FEA in subdomains, it is expected that the convergence of the interface problem is improved by improvement of precision in subdomains and the computation time is reduced by storing matrices that are results of the LU decomposition on the main memory. Then, to solve FEA in subdomains by the direct method, the A method with the Lagrange multiplier p is considered. As a result, the convergence of the interface problem is much improved by improvement of precision in subdomain-wise analysis. Then, a non-linear magnetostatic problem with 100 million degrees of freedom is solved. Moreover, the computation time is reduced by 10-20%.
