Stress field tomography based on 3D photoelasticity

M. L.L. Wijerathne, Kenji Oguni, Muneo Hori

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

A tomographic method for identification of stress fields based on 3D photoelasticity has been developed. A second order tensor field tomographic method based on the general inverse problem of 3D photoelasticity, previously developed by the authors, is found to be highly sensitive to errors in photoelastic observations. In this study a new tomographic method for stress field with fairly high robustness to errors in photoelastic observations has been developed by introducing both equilibrium condition and linear elasticity to the previously developed general tensor field tomographic method. This new stress field tomographic method expands unknown 3D stress distributions as a linear combination of independent set of basis functions and a new inverse problem is posed: identify the amplitudes of basis functions based on photoelastic observations. Just as the inverse problem of 3D photoelasticity, this newly posed inverse problem is also nonlinear and ill posed. Unlike conventional approaches to 3D photoelasticity, both these nonlinearity and ill-posedness are properly treated using a load incremental approach. Load incremental approach chops the nonlinear solution space into segments with unique solutions by conducting photoelastic observations at sufficiently small increments in external load. Validating both numerically and experimentally, it is shown that this new stress field tomographic method has sufficient robustness against errors in photoelastic observations and is applicable to experimental stress measurements.

Original languageEnglish
Pages (from-to)1065-1085
Number of pages21
JournalJournal of the Mechanics and Physics of Solids
Volume56
Issue number3
DOIs
Publication statusPublished - 2008 Mar 1

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Keywords

  • 3D stress field tomography
  • Mechanical testing
  • Nondestructive evaluation
  • Numerical algorithms
  • Optical interferometry

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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