ISMA35 Course on Modal Analysis : Theory and Practice, 23-24 September 2010

About the course

This two day course on modal analysis is organised for the 35th time by the Department of Mechanical Engineering of the Katholieke Universiteit Leuven. The course is set up as a general introduction with emphasis on data-acquisition and multi-channel modal testing. It is an intensive training course, where theoretical lectures are illustrated by numerous integrated demonstrations. A full scale multi-channel survey of a real life structure will be conducted and lectures on relevant industrial case studies are included. The mix of theory and practice gives the participants the opportunity to discuss theoretical and practical problems with experts in the field. The last part of the course touches on the practical use and applications of modal analysis ranging from trouble shooting to model updating.

Who should attend

The intensive course on Modal Analysis Theory and Practice is mainly oriented towards newcomers in the field of modal testing who have some background in the field of structural dynamics. However, since the course deals with state of the art techniques in modal testing, more experienced persons may wish to participate in order to update their knowledge.

Organising committee

K.U.Leuven, Department of Mechanical Engineering, Division of Production Engineering, Machine Design and Automation (PMA)

Prof. W. Heylen, Course Chairman,
Prof. P. Sas, Prof. D. Vandepitte, K. Vergote.

Course administrator

Mrs. L. Notré
K.U.Leuven Department of Mechanical Engineering, PMA
Celestijnenlaan 300B, B-3001 Leuven, BELGIUM
Tel (+32) 16 32 24 82; Fax (+32) 16 32 29 87
e-mail : lieve.notre(@)mech.kuleuven.be

General information

Registration fee

The registration fee is € 900. A reduction of 50% will be granted to students. Fee includes lecture notes, lunch and refreshments during break periods.

Location and language

The course takes place from 23 until 24 September 2010 on the campus of the K.U.Leuven, Celestijnenlaan 300B, B-3001 Leuven, Belgium. The course language is English.

Programme

The ISMA35 course will include following topics.

The program is divided in two days, Thursday from 8.30 until 19.00 and Friday from 8.30 until 17.30.

• Introduction
  Overview of modal analysis applications.
  
  
• Modal analysis theory
  Basic assumptions. Single and multiple degree of freedom systems. Undamped systems, proportionally and generally viscously damped systems. Frequency response function approach. Natural frequencies, damping factors, residues, modal vectors, modal participation factors, modal mass, modal stiffness, modal scaling. Demonstrations.
  
  
• Digital signal processing
  Signal types, Fourier transforms: definition and properties, related transforms. Sampling and A/D conversion, leakage errors and windows, aliasing errors and filters. Autocorrelation and autopower. Crosscorrelation and crosspower. Averaging. Frequency response function estimation: H1, H2 and Hv, coherence function. Demonstrations.
  
  
• Instrumentation
  Excitation systems, excitation hammers. Force transducers, motion transducers, transducers mounting, calibration. Measurement and analysis systems. Laser vibrometers.
  
  
• Excitation techniques
  Signal types: random, sine, pulse. Signal performance and limitations. Application on linear and non-linear systems. Multiple input/output testing.
  
  
• Demonstration and discussion
  Aim of the test, test set-up, suspension, selection of equipment, mounting of transducers, calibration, excitation set-up, hammer excitation test, shaker excitation test, frequency response function measurements.
  
  
• Modal parameter estimation
  Review and principles, frequency and time domain methods, single and multiple degree of freedom systems, local and global estimates, system order estimation tools, stability diagram, some specific methods: least squares complex exponential, least squares complex frequency domain, least squares frequency domain. Interpretation of results. Demonstration.
  
  
• Modal model validation
  Error sources, non-linearities, modal assurance criterion, mode overcomplexity, mode colinearity, frequency response function synthesis.
  
  
• Use of modal parameters
  Principles and application areas of the use of modal parameters in trouble shooting, forced response estimation, sensitivity analysis and structural dynamics modification and assembly.
  
  
• Linking analysis and test
  Correlation between numerical and experimental models, model matching, model updating. Using numerical model information for improved test set-up design.
  
  
• In-operation modal analysis techniques and case studies
  Operating mode analysis, output-only modal analysis, running mode analysis.
  
  
• Visit "Vehicle technology and lightweight construction" Laboratory