The Educational Railroading Conference Leader Since 1994


2019 Rail Transit Session


Validating Vehicle Dynamics Simulation Models

Dion Church

Dion Church

Multi-body system dynamics packages such as NUCARS®, VAMPIRE® Pro and SIMPACK occupy a growing niche in the design and qualification of rolling stock, and in the optimization of vehicle-track compatibility and wheel-rail interaction. Where outputs from vehicle dynamics simulations are to be relied upon, there exists a requirement to validate the vehicle simulation model(s) to ensure the predicted dynamic behavior reliably represents the behavior of the real vehicle. However, while the requirement for a validated simulation model is widely recognized and acknowledged, the path to achieving this goal is often less well understood. At present, comparatively little guidance exists on how to navigate through the model validation process.

This presentation provides a suggested outline for successfully carrying out a vehicle model validation exercise. The importance of vehicle testing for model validation purposes is discussed, with consideration to North American practice and context. A staged approach to carrying out the validation process is presented, encompassing both static (or quasi-static) and dynamic aspects of vehicle behavior. Common pitfalls in the validation process are identified, and real examples of ‘good’ and ‘poor’ agreement with measured test results are presented.

Included as part of the WRI’19 Rail Transit Seminar, this presentation has general applicability to the validation of dynamic simulation models of all types of rolling stock.