Laboratory for Dynamics of Machines and Structures 
Frequency domain triangulation for full-field 3D operating-deflection-shape identification
 D. Gorjup, J. Slavič and M. Boltežar
Mechanical Systems and Signal Processing, Vol. 133, p. 106287, August 2019

download pdf   video   doi.org/10.1016/j.ymssp.2019.106287
Abstract
The use of high-speed camera systems in vibration measurements is typically limited to identifying motion, transversal to the optical axis, due to an inherent limitation of 2D imaging systems. Depth information, lost in the imaging process, can be recovered by using the well-established 3D DIC technique, but is still limited to a single face of the object, observed by the stereo pair. In this research a full-field 3D operating-deflection-shape measurement technique, based on frequency-domain triangulation of image-data, is presented. A mathematical model of frequency-domain perspective transformation of small harmonic motion is introduced. This model is used to relate multiview image data to spatial amplitude spectra of the observed displacement. Using the developed method, spatial small harmonic motion of arbitrary-shaped specimen can be identified in the frequency domain using only a single, moving high-speed camera, extending the field-of-view of the established image-based vibration measurement methods.
Authors

Assistant

Domen Gorjup, PhD Student

  Ladisk, Faculty of Mechanical Engineering, University of Ljubljana
  domen.gorjup@fs.uni-lj.si
  +386 1 4771 228

Professor

Janko Slavič, PhD

  Ladisk, Faculty of Mechanical Engineering, University of Ljubljana
  janko.slavic@fs.uni-lj.si
  +386 1 4771 226
jankoslavic     jankoslavic    
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Professor

Miha Boltežar, PhD

  Ladisk, Faculty of Mechanical Engineering, University of Ljubljana
  miha.boltezar@fs.uni-lj.si
  +386 1 4771 608
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