Finite differences software for the numeric analysis of a non-destructive electromagnetic testing system
In this paper, theoretical bases for the development of a software for electromagnetic effects simulation based on the approximation method of finite differences using Scilab are presented. A methodology for programming the algorithm is discussed and a simulation test is conducted in order to validate it, which consists of a coil with a ferromagnetic core. Finally, this software is used in studies related to magnetic flux leakage by a simulation of a system for the measurement of magnetic flux density in plates with different defects, which include both 2D and 3D and defects with orientation of 45 degrees.
Comparison of Finite-Difference and Finite-Element Schemes for Magnetization Processes in 3-D Particles
This paper compares two numerical schemes for the simulation of magnetization dynamics in 3-D particles. The first one is based on the finite-difference computation of the Landau-Lifshitz equation and on the magnetostatic field evaluation by fast Fourier transforms. The second one handles the spatial discretization of the effective field expression by a nodal finite-element method and solves the Poisson equation with a finite-element/boundary-element technique. The convergence of the methods is studied by varying the time and space discretization.
Fast Semianalytical Time Integration Schemes for the Landau–Lifshitz Equation
Aiming at a micromagnetic model that describes the macroscopic material behavior starting from microstructural features, there is a need for efficient time stepping schemes for the integration of Landau-Lifshitz-equation in material samples with dimensions of order mum. This paper presents two related semianalytical time schemes. The time stepping algorithms are compared with other explicit time stepping schemes. Here, memory efficiency, time efficiency, convergence, and precision are checked. Further, special attention goes to 1) preservation of the magnetization magnitude in each FD cell; 2) a nonincrease of the free energy when applying a constant field; and 3) conservation of the systems free energy in the case of zero damping