BUTE Department of Applied Mechanics 1/35

Department of Applied Mechanics

Head: Prof Gábor Stépánhttp://www.mm.bme.hu

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Contents

• History

• People

• Education

• Research areas

• Grants / Contracts

• A case study

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HistoryMechanics at Budapest Univ Technology & Econ

1782 Institutum Geometricum-Hydrotechnicum

-1791 J Horváth -1801 J Domin

-1832 Á Tomcsányi -1834 L Gröber - (Latin)

-1850 Á Jedlik -1857 I Kruspér - (German)

-1863 V Hauszmann -1867 M Bielek - (Hungarian)

-1881 I Horváth -1913 D Nagy - (ETH Zrch)

-1941 B Bresztovszky -1959 Á Muttnyánszky

-1969 E Reuss -1995 G Béda

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Staff

Professor 2 PhD students 9

Assoc Professor 5 Prof Emeritus 2

Assistant Prof 2 Part Assoc Prof 4

Lecturer 2 Part Assist Prof 2

Res Fellow 1 Part Secretary 2

Res Assistant 1 Part Techn Staff 1

Engineer 1 Part Engineer 1

Total 14 21 35

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PeoplePhD Students 9 Tibor Gáspár

László Kovács Krisztina Németh Attila Pálfalvi Róbert Szalai András Szekrényes Péter Triesz Zsolt Vízváry Attila Zsidai

Part-time Associate Professor

4 Edit Elter-Gombkötő József Hering Lajos Pomázi Frigyes Thamm

Part-time Assistant Professor

2 Róbert Gáti György Ágoston

Part-time Secretary

2 Zsuzsa Bányai Krisztina Varga

Part-time technical 1 Irén Horváth

Positions Names Professor 2 Gábor Stépán (Head)

László Szabó Professor Emeritus 2 Gyula Béda

Elisabeth Filemon Associate Professor

5 László Kocsis Ádám Kovács Zsófi Szolgay József Uj Gábor Vörös

Assistant Professor

2 Margit Kovács-Bende Zsolt Szabó

Lecturer 2 Klára Karacs-Mindsz Tamás Insperger

Senior Research Fellow

1 András Szekeres

Research Assistant 1 Gábor Csernák Engineer 2 Richárd Wohlfart

Mihály Jurák

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People

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Courses

All the subjects in Solid Mechanics to Mech Eng students both on BSc and MSc level.

Basic subjects, delivered in each semester:BSc level Mechanics I (Statics)

Mechanics II (Strength of Matrls)Mechanics III (Dynamics)

Transition level (BSc => MSc)Applied Mechanics I (Elasticity) Applied Mechanics II

(Dynamics)

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Courses

MSc level StaticsStrength of MaterialsKinematics and DynamicsVibrationsElasticity and FEMMechanics (for Power Eng)Eng Mechanics (for Ind Manag)

Final exam closing all Mechanics subjects

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Courses

The lectures are delivered in Hungarian, English, German, French and Russian language, too.

Special MSc module in Applied Mechanics:

  Dynamics of Machines Continuum Mechanics

Elasticity Plasticity

Nonlinear Vibrations Thermomechanics

Mechanics of Polymer and Composite Structures

The department also presents Advanced Mechanics courses for the PhD program in Mech Eng.

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Research areasContinuum Mechanics Béda Elasticity and FEA Vörös, Ágoston, Németh,

Pálfalvi, Uj, Szekrényes Plasticity L. Szabó Thermoelasticity Szekeres Photoelasticity Thamm Composite & Sandwich St Uj, Pomázi, Szekrényes Structural Mechanics Kovács, Vízváry Dynamics & Vibrations Stépán, Szolgay, Zs. Szabó,

Csernák, Insperger, Szalai Mechanism Theory Filemon, Hering, Bende, Gáti Biomechanics Kocsis, Zsidai Vibration Measurement Wohlfart, Gáspár

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Publications

Publication lists are available, some papers downloadable at http://www.mm.bme.hu/

In the broad field of Mechanics, several books and lecture notes were written in Hungarian. There are two books published in English:

Gy. Béda, I. Kozák, J. Verhás, Continuum Mechanics, Akadémiai Kiadó, Budapest, 1995.

G. Stépán, Retarded Dynamical Systems: Stability and Characteristic Functions, Longman, Harlow UK, 1989.

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International organisations

IFToMM (Int Federation on Theory of Machines and Mechanisms)

ICF (Int Congress on Fracture)GAMM (Gesellschaft für Angewandte Mathematik

und Mechanik)SIAM (Soc Industrial and Applied Mathematics)Euromech – ENOC (European Nonlinear

Oscillation Conf) and CM (Comp Mechanics)UNIDO (United Nations Industrial Development

Organization)

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Editorial boards

Nonlinear Science (G. Stépán)

Meccanica (G. Stépán)

Journal of Vibration and Control (G. Stépán)

Journal of Computational and Applied Mechanics (G. Stépán)

Engineering and Automation (E. Filemon)

Periodica Polytechnica (A. Szekeres)

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Int seminar series – visitors (1997–)Dr U von Wagner Univ. Karlsruhe Prof P Elesztos TU Bratislava Prof Del Tesar Univ Texas Austin Prof C Yatomi Kanazawa Univ. Prof R C Batra Virginia PI&SU Prof S S Antman Univ. Maryland Prof J Wauer Univ. Karlsruhe Prof J Turi U Texas at Dallas Prof H Davies U New Brunswick Prof K Ruszinko TU Lvov Prof J Wittenburg Univ. Karlsruhe Prof Barrie Fraser Univ of Sidney Prof Antti Pramila Univ of Oulu Prof Eric J Hahn Univ of Sidney Prof CW Stammers Univ of Bath Prof G A Holzapfel Univ of Graz Dr B Schweizer Univ of Karlsruhe

Prof Mati Kutser Estonian Academy Prof Philip Holmes Princeton Univ. Prof S Sinha Auburn University Dr Bill Goodwine Cal Tech Pasadena Prof G Maugin Univ P et M Curie Prof A Benallal C.N.R.S. – Paris Dr Kliment Hadjov Univ of Sofia Prof Hans Troger TU Wien Prof Walter Wedig Univ. Karlsruhe Prof R Murray Cal Tech Pasadena Prof J K Banerjee Univ. Puerto Rico Dr George Haller Brown University Prof M Fayet INSA de Lyon Prof S Natsiavas Univ. Thessaloniki Prof Kirk Valanis Vancouver, WA Prof J Wittenburg Univ. Karlsruhe Prof Peter Haupt Universität Kassel Prof John Hogan University Bristol

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Computer Lab

40 computers in local network with 3 segments 4 – 4 computers in vibration & biomechanical labs 8 computers in the students' computer room

(various finite element software, computer algebraic and MATLAB compatible software, also biomechanical analysis software packages)

The common resources (file-service and -transfer, world wide web, COSMOS/M license) are provided by 2 Linux and 1 Windows2000 based servers

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Vibration Lab

Brüel&Kjaer equipment:PULSE multi-channel dynamic msrmnt system 2 electro-dyn exciters 2 signal generators, 2 amplifiers 2 digital oscilloscopes piezo accelerometers DSP cards small balancing machine shaking table

4 lab computers connected to network & devices, to PULSE system & oscilloscopes via A/D cards

Strain gauge systems, industrial weight msrmnt devices, tensile test machines + workshop

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Vibration Lab

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Biomechanics Lab

Arm movements, gait & spinal analysis:Zebris CMS-HS ultrasound based active markers’ system Instrumented treadmill with built in force plates Force platform for pressure distribution24 channels EMG unit for muscle analysesLoading by the multi fitness center

4 computers with software packages: kinematical & dynamical parameters, statistical calculation.

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Biomechanics Lab

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Research grants

International (1996-)PHARE Seismic Assessment & Verification

(Siemens, Wölfel, Westinghouse)COST P4 Nonlinear Dynamics of Machining

(6 EC research groups)EU 5 Rehabilitation Robotics (5 EC

partners)US-Hung Composite Str (Virginia SP&U)

Parametric excitation (Auburn, MSU)NKFP e-Design (Scansca FEA)

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Research grants

National (1999-)

Mechanics of Inplantants (Univ of Medicine)

Dynamic Contact Problems (Ljubljana, St.Louis)

Plastic Instability

Continuum Mechanics

Thermo-Hygro-Mechanical Systems

Dynamic Measurement System

Biomechanics Measurement System

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Research projects

Industrial (1996-)Nuclear Power Station (seismic verification of

refueling machine, buried pipes ofemergency cooling, control cables;low-cycle fatigue analyses of pipes/vessels)

Hung Oil Co. (vibration/fatigue of transfer pipe)Knorr-Bremse (vibrations in electronic control

of pneumatic brake systems)Westel, PannonGSM (vibration measurements)Bakony/Suzuki (noise reduction of electric mtrs)Power Stations (turbo-generator vibration prblm)

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Research story

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The answer

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Turbo-generator vibrations in the 90’s

Láng-BBC 215 MW turbine + Ganz generatorVibrations just above 3000 rpm at 30% low power

– critical speeds? Semi-elastic coupling Journal bearingsThermal effects Gyroscopic effectsAxial forces Engine base

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The coupling

Elasticity calculations by COSMOS/M

=>

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The bearings

Reynolds’ equation (BVP)

Non-isotropic

elasticity

(also non-conservative)

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Thermal effects

Modulus of elasticity variation with temperature Gyroscopic effects are important above 3000 rpm

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Campbell diagram – critical speeds

No critical speed problem

But: bearing 5 over-sized

base torsional mode

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Turbine blade polishing – force control

NEI Parsons

Newcastle (UK)

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Stability problems at force control

Vibrationsat the base(also formilling ofblades)

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Force control instability in RehaRob

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Stability of high-speed milling

Stability chart

and

vibrationfrequencies

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Stability of up-milling and down-milling

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Thank you for your attention.