APPLICATION OF FEM TO COUPLED ELECTRIC, THERMAL AND MECHANICAL PROBLEMS

Two problems involving coupled electric and thermal fields are investi gated by the finite element method. In a PTC thermistor the transient temperature field due to the losses is computed in each time step with the extremely non-linear dependence of conductivity on temperature ta ken into account The mechanical stresses caused by the temperature gra dient are bence obtained to facilitate the prediction of an eventual f racture of the PTC. In a second example the operation of a thermoelect ric generator based on the Seebeck effect is simulated and its structu re is optimized to attain maximal efficiency.