Coupled magneto-thermo-mechanical problems investigating high magnetic fields

Abstract

The transient magnetic field is described by Maxwell's equations. Non-linear magnetic properties of materials are considered as well as eddy currents induced in ferromagnetic regions. The temperature field is governed by the non-linear equation of temperature conduction considering temperature dependent specific heat and conductivity. Mechanical behaviour of the coil is governed by the time-dependent non-linear equilibrium equation written in terms of time-dependent displacements. Non-linearity of mechanical material properties is evaluated. The coupled magneto-thermo-mechanical analysis is performed by the FEM software ANSYS [2]. In the considered multiphysical analysis the weak coupling is performed by the right hand side vectors. Numerical experiments simulate multi-physical phenomena in pulsed magnetic fields generators. Pulsed behaviour of magnetic fields is validated by comparison with experimental measurements. The quantitative comparison of the results obtained by the linear and non-linear thermal analyses is performed. The mechanical analysis serves for prediction of the coil operation threshold. It was found, that evolution of displacements may be used as an indicator of mechanical behaviour, applied to the evaluation of coil structure integrity.