DAMPING FUNCTION ESTIMATION BASED ON MEASURED VIBRATION FREQUENCY RESPONSES AND FINITE-ELEMENT DISPLACEMENT MODES
✍ Scribed by M. DALENBRING
- Publisher
- Elsevier Science
- Year
- 1999
- Tongue
- English
- Weight
- 557 KB
- Volume
- 13
- Category
- Article
- ISSN
- 0888-3270
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✦ Synopsis
An estimation strategy for extraction of isotropic material damping is presented. The method is based on a modal receptance model, material damping functions and experimentally measured frequency response functions (FRF). Least-squares estimation of modal parameters is done by projections of the measured vibration responses onto a set of "nite-element calculated elastic displacement modes. From identi"ed modal parameters, based on the modal receptance model, a fast straightforward incremental least-squares material damping parameter estimation method is proposed. The methodology is demonstrated on two Plexiglas (PMMA) plates. Estimated material damping parameters are then validated on a third Plexiglas plate, with considerably di!erent geometry, in the frequency interval 40}500 Hz. Results from comparisons between measured and calculated frequency response functions, using direct "nite element method calculations, show extremely good agreement with respect to resonance frequency &location' and response amplitude values. Finally, sources of uncertainty between model simulation and measurements are brie#y discussed.