Course schedule

Thursday, 16 September 2021
8h30 Registration
9h00 – 9h30 Introduction
Overview of Modal analysis applications
K. Gryllias, KU Leuven, Belgium
9h30 - 10h15 Modal analysis theory (1)
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.
C. Claeys, D. Vandepitte, KU Leuven, Belgium
10h15 - 10h35 Coffee break
10h35 - 12h00 Modal analysis theory (2)
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.
C. Claeys, D. Vandepitte, KU Leuven, Belgium
12h00 - 13h00 Lunch
13h00 - 14h45 Digital signal processing & demo
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.
K. Gryllias, KU Leuven, Belgium
14h45 - 15h30 Instrumentation
Excitation systems, excitation hammers. Force transducers, motion transducers, transducers mounting, calibration. Measurement and analysis systems. Laser vibrometers.
K. Gryllias, KU Leuven, Belgium
15h30 - 15h50  Coffee break
15h50 - 16h40 Excitation techniques
Signal types: random, sine, pulse. Signal performance and limitations. Application on linear and non-linear systems. Multiple input/output testing.
K. Gryllias, KU Leuven, Belgium
16h40 - 18h10 Demonstration
K. Gryllias, KU Leuven, Belgium

 

Friday, 17 September, 2021
8h30 - 10h15 Modal parameter estimation & demo
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.
B. Peeters, Siemens PLM Software - Simcenter, Belgium
10h15 - 10h35 Coffee break
10h35 - 11h15 Modal model validation
Error sources, non-linearities, modal assurance criterion, mode overcomplexity, mode colinearity, frequency response function synthesis.
K. Gryllias, KU Leuven, Belgium
11h15 - 12h00 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.
K. Gryllias, KU Leuven, Belgium
12h00 - 13h00 Lunch
13h00 - 13h30 Visit to the Vehicle Technologies Lab
S. Gallas, KU Leuven, Belgium
13h30 - 14h15 In-operation modal analysis techniques & case studies
Operating mode analysis, output-only modal analysis, running mode analysis.
B. Peeters, Siemens PLM Software - Simcenter, Belgium
14h15 - 15h00 Linking analysis and test
Correlation between numerical and experimental models, model matching, model updating. Using numerical model information for improved test set-up design.
K. Gryllias, KU Leuven, Belgium
15h00 - 15h40 Case study 1
S. Dutré, Siemens PLM Software - Simcenter, Belgium
15h40 - 16h00 Coffee break
16h00 - 17h00 Case study 2
D. Moens, KU Leuven, Belgium