Determination of curvature and twist of deformed object by digital holographic interferometry

C. Quan, Wen Chen, C. J. Tay

Research output: Journal article publicationConference articleAcademic researchpeer-review

Abstract

This paper describes a feasibility study of digital holographic interferometry for the measurement of curvature and twist of a deformed object. Measurement of curvature and twist is an important aspect in experimental mechanics. Numerous methods have been proposed to determine the curvature and twist by using digital shearography. We proposed a novel method to determine curvature and twist based on digital holography (DH) and complex phasor (CP). In the conventional methods, phase difference between the first and second states is obtained directly by digital phase subtraction (DPS) and Fourier transform is then employed to extract phase maps. In this study, CP method is proposed to improve the quality of phase maps corresponding to second-order derivatives. Subsequently, sine/cosine transformation and short time Fourier transform (STFT) are employed to process the wrapped phase maps. An experiment is conducted on a clamped circular plate under a point load at centre. The experimental results show that the proposed method is valid and able to obtain high quality phase maps corresponding to curvature and twist of a deformed object.
Original languageEnglish
Article number73753H
JournalProceedings of SPIE - The International Society for Optical Engineering
Volume7375
DOIs
Publication statusPublished - 1 Dec 2009
Externally publishedYes
EventInternational Conference on Experimental Mechanics 2008, ICEM 2008 - Nanjing, China
Duration: 8 Nov 20088 Nov 2008

Keywords

  • Complex phasor (CP)
  • Curvature and twist
  • Digital holographic interferometry
  • Phase retrieval
  • Short time fourier transform (STFT)

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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