International workshop "Nonsmooth Phenomena in Railway Dynamics"
Date: Tue, Jun 25 2013
Hour: 10:00
Location: BCAM
Speakers: Hans True, Razvan Oprea, Egidio di Gialleonardo, Thomas Köppen
The main objective of the International Workshop "Nonsmooth Phenomena in Railway Dynamics" is to enhance the dialog between applied mathematicians and engineers within the rapidly emerging field of nonsmooth dynamical systems. During this meeting we will discuss the intrinsic value of nonsmooth models (versus smooth ones) towards explaining the dynamics of railway vehicles.
Supported by Basque Government
Date: June 25, 2013 during 10:00-17:00
Speaker(s): invited: : Hans TRUE, Razvan OPREA, Egidio di GIALLEONARDO, Thomas Köppen
Center(s): Technical University of Denmark, University "POLITEHNICA" of Bucharest, University of Cologne
Program for June 25:
9:30-10:00 Waking up coffee
10:00-10:40 Thomas Köppen
10:40-11:20 Egidio di Gialleonardo
11:20-11:50 Coffee break
11:50-12:30 Razvan Oprea
12:30-13:10 Hans True
Thomas Köppen, University of Cologne, Germany
"Design and Control of Anti-Lock Braking Systems"
Abstract: The presentation discusses different models of an anti-lock braking system (ABS). ABS are by now a standard component in every modern vehicle. Due to the characteristics of the friction coefficient, simply locking the wheels by increasing the braking torque is not effective and results in a prolonged stopping distance. Instead, ABS were introduced that prevent wheels from going into this lock situation.
There are different approaches to such control logics which are analysed by the means of non-smooth dynamical system theory. In most cases, the dynamics of the vehicle are simplified to a one-wheel model. By analysing a design based on [Tanelli et al. 2009], basic objectives and behavior of an ABS are elaborated. The presented model controlls the wheel's slip by creating stable limit cycles with certain characteristics in the corresponding phase space. Due to the control logic, the dynamical system exhibits several non-smooth switchings. Additionally, modifications to the model are proposed that can be analysed by using perturbation theory.
Egidio di Gialleonardo, Politecnico di Milano, Italy
"Non-linear dynamics of railway vehicles in curve"
Abstract: The presentation addresses the nonlinear dynamic behaviour in curves of 2-axle freight wagons and of 4-axle passenger vehicles with bogies. Non-linearities arising from wheel-rail contact and, for the freight vehicle, from dry friction in the suspension components are accounted for in the analysis. The existence of periodic solutions is investigated for a range of speeds and cant deficiency typical of the two exemplary vehicles considered. For the freight wagon case, the interaction between adjacent vehicles is also investigated considering an assembly of three cars: it is shown that the forces exchanged trough the coupling elements significantly affect the dynamics of the wagons.
Razvan Oprea, University "POLITEHNICA" of Bucharest, Romania
"Non-smooth approaches in railway vehicles dynamics"
Abstract: The key role of the wheel rail contact, the use of dry friction damping, vehicles collisions during coupling or manoeuvering, and power collection through the pantograph suggest non-smooth models as being the best suited tool to approach railway vehicles dynamics. Multibody models are used to study vertical vibrations and longitudinal or transversal dynamics of the trains. Combined multibody and finite element approaches are also aimed for the study of curve squealing of railway wheels, vertical wheel-rail interaction or pantograph-wire interaction. The main goals of the non-smooth contact dynamics employment are to achieve a proper evaluation of the system stability, improvement of the numerical efficiency and modelling specific discontinuous phenomena. The seminar will present a small number of well-chosen examples and a brief comparison between non-smooth and smooth models in railway vehicles study.
Hans True, Technical University of Denmark, Denmark
"Railway Vehicle Dynamics - a Challenge in Mathematics and Numerical Analysis"
Abstract: TBA, consult here meanwhile.
Satellite event: BCAM Dynamical Systems workshop will take place on June 26
Organiser: Oleg MAKARENKOV (omakarenkov@bcamath.org) - registration and other enquiries
Venue: BCAM, Mazarredo, 14, 48009 Bilbao, Basque Country - Spain
MAGES
Organizers:
Technical University of Denmark, University "POLITEHNICA" of Bucharest, University of Cologne, Germany
Confirmed speakers:
Hans True, Razvan Oprea, Egidio di Gialleonardo, Thomas Köppen