# ISMA Course Programme

## Programme

The programme is divided in two days:

Thursday 19 Sep. 2019 from 8h30 until 18h10 and Friday 20 Sep. 2019 from 8h30 until 17h00.

## Course programme

__Thursday, 19 September, 2019__

**•** **8h30**: Registration

**• 9h00 – 9h30**: Introduction

Overview of modal analysis applications.

*W. Heylen, 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.

*W. Heylen, 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.

*W. Heylen, 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.

W. Heylen, KU Leuven, Belgium

**• 16h40 – 18h10**: Demonstration

W. Heylen, KU Leuven, Belgium

__Friday, 20 September, 2019__

**• 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.

*F. Lembregts, 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.

*W. Heylen, 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.

*W. Heylen, 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*