Magnet dynamics using LS-DYNA®

The LS-DYNA® Electromagnetic solver (EM) has recently integrated a new monolithic FEM (Finite Element Method) – BEM (Boundary Element Method) solver along with an AMS (Auxiliary Maxwell Space) preconditioner. Eddy-Current and Magnetostatic - including linear or non-linear magnetic materials - analysis can be done thanks to these new implementations [1]. On top of this, the capability to have permanent magnets has been introduced. We will start by showing a benchmark between LS-DYNA® and ANSYS Maxwell on the force calculation between two magnets in different conditions. The first model consists of two-cylinder magnets at a distance d. The magnet is a Neodymium Iron Boron magnet with a magnetic coercivity of -900 kA/m. In the first comparison, a linear magnetic characteristic of the magnet is considered. Then a non-linear BH curve is introduced in the next comparison. The insulator is a linear material with no conductivity. In the second model, we added a steel plate with high permeability between the 2 magnets to see its influence on the force on each magnet. The benchmark gives a good agreement between Ansys-Maxwell and LS-DYNA® in terms of results and computational cost in both linear and nonlinear case.