There is a simple Simulink-based example at this page. In this Simulink tutorial, a train is modeled as a two-mass system with springs and dampers, which is a starting point, I suppose.
If you have access to Simscape, you can model masses, springs, dampers, etc. using a less mathematical and more component-based approach. This page provides instructions on how to use Simscape.
A more specialized thing that comes to mind is the Vehicle Body block in SimDriveline. Even though it models a two-axle vehicle, you can maybe string a bunch of these blocks together if applicable. Otherwise, the equations of motion are described in the documentation and you can extend these to include multiple axles per car as needed.
- Sebastian
