I'm just running the examples, in order to learn new things. I'm really looking for non-linear properties, and I mostly see linear and bi-linear materials. As I've said before, these codes, such as the one I'm using (Impact), are built totally around Newton's F=ma. There are no eigenvalues, modes, and other horrible California assumptions.
This next example has been quite important in seismic engineering - the sliding block. This example just shows a pushed block sliding, but could be extended to blocks sliding under seismic shaking. I had done this at work, with the fancy analysis packages. If you could get dynamic friction, then you could start to model earthquake fault rupture.