Hello,
I am curious to understand the differences between linear and nonlinear modeling of the track in train-track interaction systems in practice.

For linear tracks, Simpack accepts a reduced model of the track with a limited number of eigenmodes, while for nonlinear modeling this reduction is not carried out. Also, all the interface nodes are retained for post-processing.

On another note, the Simpack documentation mentions Craig-Bampton substructuring being carried out for this particular application. Is this done only for the nonlinear case? This would be coherent with my statement above regarding interface nodes, but I haven't found any certain evidence that this is indeed what happens under the hood.

Thanks.