Approaches for going beyond linear frequency domain powertrain simulations

The study of powertrain multi-body systems in time-domain can be prohibitively expensive for systems with high rotational speeds. Solving the equations of motion in frequency-domain can provide orders of magnitude faster results when omitting non-linear force components, allowing to separate the problem into independent equations for each load frequency. However, this feature is lost when accounting for non-linearities, e.g. from gear meshing. We present an iterative algorithm, that avoids coupling of frequency components by switching between frequency- and time-domain for describing the non-linear terms. Utility of the algorithm is demonstrated by studying a two-shaft model system, comparing solution by time-domain integration and by the iterative algorithm