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Updated: Jul 14, 2026

Measurement of Chladni Mode Shapes with an Optical Lever Method
Published on: June 5, 2020
Multipoint laser vibrometer for modal analysis
William N MacPherson1, Mark Reeves, David P Towers
1School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, UK. w.n.macpherson@hw.ac.uk
Abstract:
Experimental modal analysis of multifrequency vibration requires a measurement system with appropriate temporal and spatial resolution to recover the mode shapes. To fully understand the vibration it is necessary to be able to measure not only the vibration amplitude but also the vibration phase. We describe a multipoint laser vibrometer that is capable of high spatial and temporal resolution with simultaneous measurement of 256 points along a line at up to 80 kHz. The multipoint vibrometer is demonstrated by recovering modal vibration data from a simple test object subject to transient excitation. A practical application is presented in which the vibrometer is used to measure vibration on a squealing rotating disk brake.
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