Railway Dynamics
Research focus
The Peer review has evaluated this group as Excellent
The Railway Dynamics unit carries out research into the dynamic behaviour of railway vehicles and their interaction with the infrastructure, with a critical mass of senior research competence. Research is directed towards dynamics, vibration and durability problems of railway vehicles and their interaction with the infrastructure, special emphasis being set on the combined application of mathematical modelling and experimental. Continuing interaction with and financial support by the main Italian and European industrial stakeholdes (among others Alstom Transport, Bombardier Transportation, AnsaldoBreda, Lucchini, Trenitalia, Rete Ferroviaria Italiana, SNCF, DB) is achieved through industry funded projects and participation into EC funded research within FP5 and FP6. This ensures research to be focused on the actual needs of rail industry. Technology transfer is also addressed and several research results have found industrial implementation, as attested e.g. by the participation of the group in the design of the new AnsaldoBreda high-speed train V250 for Belgium and the Netherlands [RWD-PRF-4], and in a large project 51 for diagnostics and condition monitoring of the Italian HS lines being undertaken by RFI (Italian infrastructure manager). Four main research subjects may be identified for the group as described below: Mathematical modelling and experimental investigation of rail vehicle running dynamics and train-track interaction The unit has been producing innovative approaches to modelling rail vehicle running dynamics and train-track bridge interaction. Main strengths of these model are represented by wheel-rail contact models including three-dimensional and multiple contact effects [RWD-RP-1], [RWD-RP-3] and by the description of track flexibility effects, based on a finite element approach whereas the present state of the art generally relies on simpler models. Modelling and simulation methods were validated by comparison with line measurements on vehicles of different classes ranging from urban to high speed ([RWD-RP-2], and other references before the reporting period) and on a full scale roller rig, [RWD-RP-1], [RWD-RP-3], [RWD-RP-5]). Several research links are active with the most relevant research groups in the world, including TTCI (a subsidiary of the Association of American Railroads), Chalmers University Goteborg, INRETS (France), KTH Stockholm, DLR Oberpfaffenhofen. Recognition of the group’s international stature is also attested by involvement in important research projects at the international level. As an example, Prof. Bruni was consultant to the USA engineering and construction company Parsons for railway runability within the Project Management Consulting for the Messina Suspension Bridge. Pantograph-catenary interaction The unit holds a world leading position into modelling and simulation of pantograph-catenary interaction. Results of this work are now being partly incorporated into the EUROPaCaS simulation code, a joint cooperation of SNCF, DB, Polimi and IST (Istituto Superior Tecnico) Lisbon. Research work of the unit also covers electrical and tribological aspects of pantograph-catenary contact [RWD-RP-7]. As a main part of this research, a test bench for pantograph-catenary contact was [RWD-RP-6]. Aerodynamics of high speed pantographs is also being investigated in the Polimi wind tunnel testing facility [RWD-RP-8]. Finally, the unit is strongly involved in research on active pantograph control, as described in the next paragraph Mechatronics of railway vehicles Active control applications are studied as a mean to improve rail vehicle performances, safety and ride quality. Recent researches have concentrated on: - active control of suspensions to improve vehicle stability and curving behaviour [RWD-RP-9], with main emphasis on designing and testing an “active yaw damper” [RWD-RP-10], now being further developed by TiVeT (see section 1.5). - active pantograph control to improve the quality of current collection, ensure interoperability (use of the vehicle across different countries), reduce wear and damage on the contact wire and on the collector strips [RWD-RP-11]. - testing of pantographs by using Hardware in the loop (HIL) test stands. 52 Cooperation on these subject is open with some of the most important research groups in the world, e.g. the one leaded by Prof. R.M. Goodall in the UK, and cooperation with DB and SNCF is foreseen in FP7 . Aerodynamics of railway vehicles This is a relatively recent research line, started after the opening of the Polimi wind tunnel. Research mainly deals with the effect of crosswinds on high-speed vehicle running dynamics and ride safety [RWD-RP-12], [RWD-RP-13]. Despite the recent start of this research subject, important achievements have already been reached at the European level, see subsection “Achievements”, and strong links with the world’s leading research groups, e.g. the one leaded by Prof. C. Baker at the University of Birmingham have been established.
Dipartimento di afferenza
Docenti afferenti
Full Professors
Stefano Bruni
Federico Cheli
Andrea Collina
Giorgio Diana
Renato Manigrasso
Bruno Pizzigoni
Associate Professors
Roberto Corradi
Assistant Professors
Paolo Belforte
Francesco Braghin
Alan Facchinetti
Stefano Melzi
Gisella Tomasini