Simulations of transient thermal and electrical behavior of contact spots

The problem of the influence of transient current pulses on the physical conditions in electrical contacts has been addressed by conducting simulations of the coupled thermal and electrical response of contact spots of two different sizes to transient currents. For this purpose, we have used SPECTRUM; a multi-physics finite element method package capable of handling coupled nonlinear thermal and electrical 3D systems. From the simulations, we see that the uniform temperature distribution in the steady state case is not preserved when subjecting the contact to a transient current, but instead the temperature is elevated around the rim of the spots. Also, a smaller spot becomes substantially hotter than a larger spot, and could therefore be expected to grow and age faster, although this hypothesis is not proven experimentally in the present study.