Abstract:
"Introduction of an Electromagnetism Module in LS-DYNA for Coupled Mechanical-Thermal-Electromagnetic Simulations"
This paper introduces a new electromagnetism module being developed for the LS-DYNA software, designed to perform fully coupled mechanical-thermal-electromagnetic simulations. A primary application for this module is Electromagnetic Metal Forming (EMF), a high-velocity forming process where magnetic forces, generated by induced currents, are used to shape a workpiece. The module solves the Maxwell equations within the Eddy current approximation, utilizing a Finite Element Method (FEM) for the solid conductors and a Boundary Element Method (BEM) for the surrounding air or vacuum, which conveniently eliminates the need to mesh the surrounding space. The computed electromagnetic fields generate a Lorentz force that is passed to the mechanical solver to produce deformations and a Joule heating term for the thermal solver, which can, in turn, affect the material's electromagnetic properties. The module's capabilities are first validated against a ring expansion experiment, where a current in a solenoid coil repels and expands a metal ring; the simulation's results for induced current and ring radius showed very good agreement with the experimental data. A second example demonstrates a typical EMF application of forming a thin metal sheet, illustrating how the simulation can track the magnetic field diffusion and resulting force distribution to help optimize the process.
