Project: Accurate Rail-to-Wheel Contact Simulation

This project aims towards an easy-to-use simulation environment for a faster and more accurate and convenient prediction of the safety, wear, fatigue and noise generation behavior of railway wheels on the rails. This shall be achieved by creating an interface between the two leading simulation software packages SIMPACK Rail and CONTACT and by a drastic speed-up of the CONTACT software along with a further improvement of its capabilities needed for a realistic simulation of the rail-to-wheel contact. SIMPACK Rail is owned by SIMPACK AG and CONTACT by VORtech BV, both R&D performing SME's and technology leaders in the fields under consideration._x000D__x000D_SIMPACK Rail is an advanced simulation software package for the simulation of the running behavior of complete railway vehicle systems on the track. It is used by rail vehicle manufacturers, railway operators and research institutes world-wide, for the design and operation of railway systems. It is based on the so-called multi-body approach, also called a vehicle system dynamics (VSD) approach, which covers also mechatronic aspects. The software computes the dynamic movement of and interactions between the different components of the system under consideration, that is, the vehicle or train with its components and the track. _x000D__x000D_An important aspect in these simulations concerns the frictional interaction between wheels and rails. On the one hand, the forces between wheels and rails which arise from this interaction determine directly the_x000D_dynamic behavior of the railway vehicle within the track (forces exerted on the track and vehicle, running stability, derailment safety). On the other hand, the wheel and rail material is influenced by these forces in_x000D_terms of wear and rolling contact fatigue (RCF), which are two of the largest cost factors for track and vehicle COtenance._x000D__x000D_Due to the geometrically and tribologically difficult contact situation, the computational effort for predicting the forces and the resulting wear and RCF is still very high. Thus, currently only approximate models are_x000D_used for simulating this interaction within a VSD approach. This limits the predictive power of current multi-body software, primarily for the simulation of wear and RCF processes which depend on the distribution of frictional stresses in the contact patch, but also for the overall dynamic behavior of the vehicles that are studied._x000D__x000D_In the past years, the need for an accurate and fast simulation of the contact behavior of wheels and rails has been quickly growing. The approximate models used in VSD software so far do not accurately represent railway wheels running in flange contact, non-steady effects (relevant for noise generation and short wavelength wear processes), and the contribution of temperature, contaminations or lubricants, as well as to the precise distribution of tangential stresses over the contact patch, which is the dominant factor in wear processes. At the same time, a direct coupling between VSD and advanced contact mechanics software, which would allow the most realistic consideration of the vehicle dynamics for the contact simulation, is not yet possible due to the required calculation times._x000D__x000D_CONTACT is the primary candidate for filling in these needs. It is an advanced simulation model and software tool for computing the frictional contact between wheels and rails. It is considered as the standard reference for the approximate models mentioned before. However, there currently are certain restrictions on its use in VSD software. In order to convince the potential customers we must achieve considerable speedup of the calculations and accuracy improvements as well._x000D__x000D_The purpose of the project is twofold:_x000D__x000D_ 1. to allow direct usage of the CONTACT software during a full vehicle system simulation within SIMPACK Rail, particularly for wear and RCF predictions, and_x000D__x000D_ 2. to improve the CONTACT software in order to increase its value for VSD simulations:_x000D_ 2.a. to make it faster, and thereby enable for the first time its full use in VSD simulations;_x000D_ 2.b. to improve its accuracy with respect to conformal contact as occurs in flanging contact, and thereby improve the advantage over approximate models;_x000D_ 2.c. to improve its accuracy with respect to non-steady effects and the friction processes, e.g. include effects of temperature, contamination or lubricants, and thereby improve the predictive power of the combined product consisting of SIMPACK Rail with the CONTACT add-on._x000D__x000D_This creates a product called the "CONTACT add-on" that is relevant to the current users of SIMPACK Rail, and that allows them to improve wheel and rail profiles with respect to COtenance costs and safety issues, improve the dynamic stability (speed and comfort) of railway vehicles, and reduce the noise generated by trains._x000D_

Acronym	ACCURCOS (Reference Number: 5512)
Duration	01/06/2010 - 31/05/2013
Project Topic	To create a simulation environment for a faster and more accurate and convenient prediction of the safety, wear, fatigue and noise generation behavior of railway wheels on the rails, achieved by coupling for the first time two advanced software simulation tools.
Project Results (after finalisation)	The software CONTACT was successfully integrated into the software SIMPACK Rail, which makes it much more easily accessible to railway engineers, rail-wheel contact specialists. research institutes and universities than as as stand-alone software. A basis for further extensions of CONTACT was created, e.g. for advanced contact models and an interface to the detailed calculation of wheel and rail wear.
Network	Eurostars
Call	Eurostars Cut-Off 4

Project partner

Number	Name	Role	Country
2	SIMPACK AG	Partner	Germany
2	VORtech BV	Coordinator	Netherlands