Experimental Mechanics

, Volume 37, Issue 4, pp 387–392 | Cite as

Filtering thermoelastically measured isopachic data

  • B. J. Rauch
  • R. E. Rowlands


This paper describes a numerical filter for removing noise from thermoelastically measured isopachic information. The filter is based on the isotropic compatibility equation and uses a least squares fit to a general solution of Laplace's equation. The fact that relevant mechanics of the measured data are incorporated into the filtering algorithm causes the filtered data to converge to a quality solution. The technique is demonstrated with illustrative examples, including the use of measured input information.


Mechanical Engineer Fluid Dynamics General Solution Quality Solution Input Information 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Rauch, B.J. and Rowlands, R.E., “Thermoelastic Stress Analysis,” Handbook on Experimental Mechanics, 2nd ed., A.S. Kobayashi, ed. (1993).Google Scholar
  2. 2.
    Huang, Y.M., “Determination of Individual Stresses from Thermoelastically Measured Trace of Stress Tensor,” Ph.D. thesis, University of Wisconsin-Madison (1989).Google Scholar
  3. 3.
    Huang, Y.M., Rowlands, R.E., andLesniak, J.R., “Simultaneous Stress Separation, Smoothing of Measured Thermoelastic Isopachic Information and Enhanced Boundary Data,” EXPERIMENTAL MECHANICS,30,398–403 (1990).Google Scholar
  4. 4.
    Huang, Y.M., AbdelMohsen, H.H., andRowlands, R.E., “Determination of Individual Stresses Thermoelastically,” EXPERIMENTAL MECHANICS,30,89–94 (1990).Google Scholar
  5. 5.
    Huang, Y.M. andRowlands, R.E., “Quantitative Stress Analysis Based on the Measured Trace of the Stress Tensor,”J. Strain Analysis,26,55–63 (1991).Google Scholar
  6. 6.
    Rauch, B.J., “Enhancement and Individual Stress Component Separation of Thermoelastically Measured Isopachic Data,” Ph.D. thesis, University of Wisconsin-Madison (1993).Google Scholar
  7. 7.
    Rauch, B.J. andRowlands, R.E., “Determining Reliable Edge Isopachic Data from Interior Thermoelastic Measurements,” EXPERIMENTAL MECHANICS,35,174–181 (1986).Google Scholar
  8. 8.
    Feng, Z., Zhang, D., Rowlands, R.E., andSandor, B.I., “Thermoelastic Determination of Individual Stress Components in Loaded Composites,” EXPERIMENTAL MECHANICS,32,89–95 (1992).CrossRefGoogle Scholar
  9. 9.
    Boyle, J.T. and Hamilton, R., “A Method of Thermographic Stress Separation,” Fourth Conf. Applied Solid Mechanics, Elsevier, A.R.S. Porter, ed., University of Leicester (1991).Google Scholar
  10. 10.
    Ryall, T.G. andWong, A.K., “Determining Stress Components from Thermoelastic Data—A Theoretical Study,”Mech. Mater.,7,205–214 (1988).CrossRefGoogle Scholar
  11. 11.
    Ryall, T.G., Heller, M., and Jones, R., “Determination of Stress Components from Thermoelastic Data Without Boundary Conditions,” (1991).Google Scholar
  12. 12.
    Ryall, T.G., Cox, P.M., and Enke, N.F., “On the Determination of Dynamic and Static Stress Components from Experimental Thermoelastic Data,” (1991).Google Scholar
  13. 13.
    Stanley, P., “Stress Separation from SPATE Data for a Rotationally Symmetrical Pressure Vessel,”Stress and Vibration: Recent Developments in Industrial Measurement and Analysis,SPIE 1084,P. Stanley, ed.,72–83 (1987).Google Scholar
  14. 14.
    Lin, S.T., “Quantitative Thermoelastic Stress Analysis of Orthotropic Composite Structures,” Ph.D. preliminary thesis, University of Wisconsin-Madison (1994).Google Scholar
  15. 15.
    AbdelMohsen, H.H., Huang, Y.M., andRowlands, R.E., “Hybrid Elastostatic and Thermostatic Analysis from Measured Data,” EXPERIMENTAL MECHANICS,29,474–480 (1989).CrossRefGoogle Scholar
  16. 16.
    Lin, S.T. andRowlands, R.E., “Thermoelastic Stress Analysis of Orthotropic Composites,” EXPERIMENTAL MECHANICS,35,257–265 (1965).Google Scholar
  17. 17.
    Lin, S.T. and Rowlands, R.E., “Hybrid Stress Analysis.” Google Scholar
  18. 18.
    Stanley, P. andDulieu-Smith, J.M., “Devices for the Experimental Determination of Individual Stresses from Thermoelastic Data,”Strain Analysis,31,53–63 (1996).Google Scholar
  19. 19.
    Lin, S.T., Miles, J.P., andRowlands, R.E., “Image Enhancement and Stress Separation of Thermoelastically Measured Data Under Random Loading” EXPERIMENTAL MECHANICS,37,225–231 (1997).CrossRefGoogle Scholar
  20. 20.
    Stanley, P. andChan, W.K., “The Determination of Stress Intensity Factors and Crack-tip Velocities from Thermoelastic Infra-red Emissions,Proc. Int. Conf. Fatigue Eng. Mater. Struct.,1,105–114 (1986).Google Scholar
  21. 21.
    Stanley, P. and Chan, W.K.,“Mode II Crack Studies Using the SPATE Technique,” Proc. Int. Conf. Exp. Mech., 916–923 (1986).Google Scholar
  22. 22.
    Chan, S.W.K. andTubby, P.J., “Stress Intensity Factors for Toe Cracks in Fillet Welded Joints—Finite Element Modeling and Thermoelastic Determination,”Stress and Vibration: Recent Developments in Industrial Measurements and Analysis, Incorporating Third International Conference on Stress Analysis by Thermoelastic Technique,SPIE 1084,P. Stanley, ed., London,116–118 (1987).Google Scholar
  23. 23.
    Hawong, J.S., Suh, J.G., and Rowlands, R.E., “Measuring Stress Intensity Factors in Orthotropic Materials Using SPATE,” Int. Conf. Struct. Failure Product Liability Tech. Assurance, Vienna (1995).Google Scholar
  24. 24.
    Lin, S.T., Feng, Z., and Rowlands, R.E., “Thermoelastic Determination of Stress Intensity Factors in Orthotropic Composites Using the J-integral,” Eng. Fract. Mech.Google Scholar
  25. 25.
    Pukas, S.R., “Theoretical Considerations for Determining Stress Intensity Factors via Thermoelastic Stress Analysis,” Proc. 2nd Int. Conf. Stress Analysis Thermoelastic Tech., London, 88–101 (1987).Google Scholar
  26. 26.
    Leaity, G.P. andSmith, R.A., “The Use of SPATE to Measure Residual Stresses and Fatigue Crack Growth,”Fatigue Fract. Eng. Mater. Struct.,12,271–282 (1989).Google Scholar
  27. 27.
    Lukasiewicz, S.A., Stanuszek, M., andCzyz, J.A., “Filtering of Experimental Data in Plane Stress and Strain Fields,” EXPERIMENTAL MECHANICS,23,139–147 (1993).Google Scholar
  28. 28.
    Hildebrand, F.B., Advanced Calculus for Applications, 2nd ed., John Wiley, New York (1989).Google Scholar

Copyright information

© Society for Experimental Mechanics, Inc. 1997

Authors and Affiliations

  • B. J. Rauch
    • 1
  • R. E. Rowlands
    • 2
  1. 1.John Deere Industrial Equipment DivisionDubuque
  2. 2.Department of Mechanical EngineeringUniversity of WisconsinMadison

Personalised recommendations