Main Article Content

Abstract

In photoelasticity, the method of obtaining the individual values of principal stresses/normal stresses separately is referred to as stress separation. For stress separation, one needs the value of fringe order and the isoclinic angle free of noise over the domain. With improved data acquisition and smoothing methodologies, it has now become possible to get accurate and smooth variation of the fringe order and the isoclinic value over the domain. This has been discussed in detail in Part-A of this article. Shear difference is one of the widely used techniques for stress separation in photoelasticity. Though it is a line byline technique, a whole field evaluation of stress separation using this technique and its representation is shown in this paper. It is observed that spikes in isoclinic values lead to streak formation in the whole field representation of separated stress components. The use of outlier algorithm for smoothing isoclinic and isochromatic data has removed these streaks and has also greatly improved the accuracy of the separated stress components. The various issues related to digital implementation such as boundary pixel identification, grids for accommodating the various boundaries etc. are given in the Appendix. Performance of the methodology is verified for simply and multiply connected objects. The models are subjected to moderate loads to have sufficient isochromatic-isoclinic interaction. The stress components obtained are smoothed with the outlier algorithm for improved accuracy. Whole field separated stress values are obtained for the domains considered.

Keywords

no keywords

Article Details

How to Cite
M. Ramji, & K. Ramesh. (2023). Stress Separation in Digital Photoelasticity Part B - Whole Field Evaluation of Stress Components. Journal of Aerospace Sciences and Technologies, 60(1), 16–25. https://doi.org/10.61653/joast.v60i1.2008.812

References

  1. Ramesh, K., "Digital Photoelasticity: Advanced Techniques and Application", Springer-Verlag, Berlin, Germany, 2000.
  2. Haake, S. J. and Patterson, E. A., "The Determination of Principal Stresses from Photoelastic Data", Strain, Vol. 28, pp. 153-158, 1992.
  3. Drucker, D. C., "Photoelastic Separation of Principal Stresses by Oblique Incidence", J. App. Mech., A156-A160, 1943.
  4. Frocht, M. M., "Discussion of ref. [3]", J. App. Mech., 1944, A125-A126.
  5. Brown, G. M. and Sullivan, J. L., "The Computeraided Holophotoelastic Method", Exp. Mech., Vol.
  6. , No. 2, pp. 135-144, 1990.
  7. Yoneyama, S., Morimoto, Y. and Kawamura, M., "Two-dimensional Stress Separation Using PhaseStepping Interferometric Photoelasticity", Meas. Sci.Tech., Vol. 16, pp. 1329-1334, 2005.
  8. Zhenkun, L., Hai, Y., Dazhen, Y. and Yilan, K., "Numerical Analysis Of Phase-stepping Interferometric Photoelasticity for Plane Stress Separation", Opt. and Lasers Eng., Vol. 45, No. 1, pp.7782, 2007.
  9. Barone, S. and Patterson, E. A., "Full Field Separation of Principal Stresses by Combined Thermo- and Photo-elasticity", Exp. Mech., Vol. 36, No. 4, pp.318-324, 1996.
  10. Nurse, A. D., "Photoelastic Stress Separation Using Fast Fourier transforms", Proc. Int. Conf. Exp. Mech.
  11. (Ed. I.M. Allison), Oxford, 24th - 28th August, pp.559-562, 1998.
  12. Ramesh, K. and Mangal, S. K., "Whole Field Stress Separation by Oblique Incidence Using Phase-shifting Technique", Proc. Int. Conf. Exp. Mech. (ICEM), Singapore, 29th November - 1st December, 2000.
  13. Berghaus, D. G., "Combining Photoelasticity and Finite Element Method for Stress Analysis Using Least Squares", Exp. Mech., Vol. 31, pp. 36-41, 1991.
  14. Mangal, S. K., Pathak, P. M., and Ramesh, K., "Use of Finite Element for Stress Separation in Digital Photoelasticity", J. Aero. Soc. India, Vol. 51, No. 4, pp. 205-213, 1999.
  15. Umeagukwu, C., "Application of Photoelastic and Boundary Element Methods to Stress Analysis", Int.
  16. J. of Mech. Eng. Edu., Vol. 17, pp. 163-174, 1989.
  17. Mitsui, Y. and Yoshida, S. Y., "Boundary Element Method Applied to Photoelastic Analysis", ASCE J.
  18. Eng. Mech, Vol. 109, pp. 619-631, 1983.
  19. Chen, D., Becker, A. A., Jones, I. A., Hyde, T. H. and Wang, P., "Development of New Inverse Boundary Element Techniques in Photoelasticity", J. Strain Analysis for Eng. Des., Vol. 36, pp. 253-264, 2001.
  20. Segerlind, L. J., "Stress-difference Elasticity and its Application to Photomechanics", Exp. Mech., Vol.
  21. , pp. 441-445, 1971.
  22. Chandrashekhara, K. and Abraham Jacob, K., "An Experiment-numerical Hybrid Technique for Twodimensional Stress Analysis", Strain, Vol. 13, pp. 25-31, 1977.
  23. Quiroga, J. A. and Gonzalez-Cano, A., "Stress Separation from Photoelastic Data by a Multigrid Technique", Meas. Sci. Tech., Vol. 9, pp. 1204-1210, 1998.
  24. Frocht, M. M., "Photoelasticity, Vol.1", John Wiley and Sons, Inc., NewYork, 1962.
  25. Case, R. O. and Barkoff, A. C., "Computer-assisted Reduction of Two-dimensional Photoelastic ShearDifference Data", Exp. Tech., pp. 32-37, 1986.
  26. Trebuna F., "Some Problems of Accelerating the Measurements and Evaluating the Stress Fields by the Photostress Method", Exp. Tech., Vol. 14, pp. 36-40, 1990.
  27. Haake, S. J., Patterson, E. A. and Wang, Z. F., "2D and 3D Separation of Stresses Using Automated Photoelasticity", Exp. Mech., Vol.36, No. 3, pp. 269276, 1996.
  28. Xue-Feng, Y., Long-Hui, J., Wei, X., Guan-Chang, J. and Hsien-Yang, Y., "Digital Shifting Photoelasticity with Optical Enlarged Unwrapping Technology for Local Stress Measurement", Opt. and Lasers
  29. Tech., Vol. 37, No.7, pp. 582-589, 2005.
  30. Patterson, E. A. and Wang, Z. F., "Towards Full-field Automated Photoelastic Analysis of Complex Components", Strain, Vol. 27, No. 2, pp. 49 - 56, 1990.
  31. Vadovic, F., "Contribution to the Analysis of Errors in Photoelasticity", Exp. Mech., Vol. 5, No. 12, pp.
  32. -416, 1965.
  33. Mangal S. K. and Ramesh. K., "Use of Multiple Loads to Extract Continuous Isoclinic Fringes by
  34. Phase-shifting", Strain, Vol. 35, No. 1, pp. 15-17,1999 and its errata in Vol. 35, No. 2, pp. 76, 1999.
  35. Ajovalasit, A., Barone, S., Petrucci, G., "A Method for Reducing the Influence of the Quarter Wave Plate
  36. Error in Phase Shifting Photoelasticity", J. Strain Analysis Eng. Des., Vol. 33, No. 3, pp. 207-216,
  37. Math Works, Inc., "Curve Fitting Toolbox Ref. User’s Guide", Math Works, Inc., Natick, MA, 2005.
  38. Timoshenko, S. P. and Goodier, J. N., "Theory of Elasticity", McGraw - Hill, Singapore, 1987.

Similar Articles

<< < 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 > >> 

You may also start an advanced similarity search for this article.