Department%20of%20Applied%20Mechanics

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Department of Applied Mechanics
Head Prof Gábor Stépán http//www.mm.bme.hu
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Contents

• History
• People
• Education
• Research areas
• Grants / Contracts
• A case study

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History

• Mechanics 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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People
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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 gt MSc)
• Applied Mechanics I (Elasticity)
• Applied Mechanics II (Dynamics)

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Courses

• MSc level Statics Strength of
  Materials Kinematics and Dynamics Vibrations
  Elasticity and FEM Mechanics (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 areas
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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)
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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

• BrüelKjaer 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 analysisZebris
  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
  SPU) 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
  of emergency 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 90s

• Láng-BBC 215 MW turbine Ganz generator
• Vibrations just above 3000 rpm at 30 low power
  
  critical speeds?
• Semi-elastic coupling Journal bearings
• Thermal effects Gyroscopic effects
• Axial forces Engine base

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The coupling

• Elasticity calculations by COSMOS/M
• gt

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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.