Vibration measurement using additive speckle interferometry

Liusheng Wang, Pavel Fomitchov, Sridhar Krishnaswamy

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Scopus citations

Abstract

A method for obtaining structural vibration amplitudes quantitatively is proposed based on the stroboscopic speckle interferometer. The technique requires five frames of additive speckle patterns: the first one (SO) taken with the laser illumination pulsed at instants when the vibration achieves its two zero amplitude positions within one sinusoidal vibration cycle of the specimen; and the remaining four (SI through S4) taken with the illumination pulses arranged at times when the vibration is at its maximum and minimum amplitudes. During the acquisition of speckle patterns SI through S4, the phase of the reference beam is appropriately shifted between the two pulses within each vibration cycle. The last four speckle patterns are then subtracted from the first one to yield four correlation fringe patterns with relative phase shifts of 0, nil, n and 3ji/2 respectively. These fringe patterns are then utilized to derive a phase map using a four-step phase calculation algorithm and finally the vibration amplitude and the sign of the vibrational nodes can be readily obtained from the phase map quantitatively. Results have been obtained using a speckle shearographic setup for the vibration measurement of a flat bottom-holed aluminum specimen vibrating at different frequencies.

Original languageEnglish (US)
Title of host publication15th Biennial Conference on Mechanical Vibration and Noise - Vibration Control, Analysis, and Identification
PublisherAmerican Society of Mechanical Engineers (ASME)
Pages1407-1415
Number of pages9
ISBN (Electronic)9780791897669
DOIs
StatePublished - 1995
EventASME 1995 Design Engineering Technical Conferences, DETC 1995, collocated with the ASME 1995 15th International Computers in Engineering Conference and the ASME 1995 9th Annual Engineering Database Symposium - Boston, United States
Duration: Sep 17 1995Sep 20 1995

Publication series

NameProceedings of the ASME Design Engineering Technical Conference
Volume3C-1995

Conference

ConferenceASME 1995 Design Engineering Technical Conferences, DETC 1995, collocated with the ASME 1995 15th International Computers in Engineering Conference and the ASME 1995 9th Annual Engineering Database Symposium
Country/TerritoryUnited States
CityBoston
Period9/17/959/20/95

ASJC Scopus subject areas

  • Mechanical Engineering
  • Computer Graphics and Computer-Aided Design
  • Computer Science Applications
  • Modeling and Simulation

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