A Portable Optical DSPI System for Residual Stresses Measurement by Hole Drilling Using the Integral Method in Terms of Displacement

Article PDF

A Portable Optical DSPI System for Residual Stresses Measurement by Hole Drilling Using the Integral Method in Terms of Displacement

A.G. Albertazzi, M. Viotti, C. Veiga

download PDF

Abstract. A portable optical device for residual stresses measurement is presented here. It combines an achromatic digital speckle pattern interferometer (DSPI) with radial sensitivity with a high speed pneumatic drilling unit. The system automatically acquires a 1280 x 960 pixel image for each step of incremental hole drilling. The number of drilling steps, as well the drilling increments, is fully programmable. The data is processed and fitted to a set of displacement curves obtained by the Finite Element Method according to the integral formulation. This paper describes the device as well as the data reduction procedure. The system has been applied to measure residual stress profiles in four to eight points of cross-sections of pipes and, from that, to compute the amount of bending moment induced in pipelines used for oil transportation. The paper presents results of a calibration test in a 12 m long test bench with a 200 mm steel diameter pipe.

Keywords
Residual Stress Measurement, Incremental Hole Drilling, ESPI, DSPI, Integral Method

Published online 12/22/2016, 6 pages
Copyright © 2016 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA

Citation: A.G. Albertazzi, M. Viotti, C. Veiga, ‘A Portable Optical DSPI System for Residual Stresses Measurement by Hole Drilling Using the Integral Method in Terms of Displacement’, Materials Research Proceedings, Vol. 2, pp 449-454, 2017

DOI: http://dx.doi.org/10.21741/9781945291173-76

The article was published as article 76 of the book Residual Stresses 2016

Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

References
[1] Schajer, G. S. (Editor), “Practical Residual Stress Measurement Methods”, Wiley 2013, 7, ISBN 9781118342374.
[2] ASTM E837-13. “Standard test method for determining residual stresses by the hole-drilling strain-gage method”, Annual Book of ASTM Standards. American Society for Testing and Materials (2013).
[3] Schajer, G.S. and Rickert, T.J., “Incremental Computation Technique for Residual Stress Calculations Using the Integral Method”, Exp. Mech., 51(7), 1217-1222 (2011). http://dx.doi.org/10.1007/s11340-010-9408-5
[4] Viotti, M. R., Kapp W. and Albertazzi Jr., A. “Achromatic digital speckle pattern interferometer with constant radial in-plane sensitivity by using a diffractive optical element,” App. Opt. 48(12), 2275-2281 (2009). http://dx.doi.org/10.1364/AO.48.002275
[5] Viotti, M. R., Albertazzi Jr., A. and Kapp, W. A., “Experimental comparison between a portable DSPI device with diffractive optical element and a hole drilling strain gage combined system,” Opt. Lasers Eng. 46 (11), 835-841 (2008). http://dx.doi.org/10.1016/j.optlaseng.2008.05.020
[6] Viotti, M. R. and Albertazzi Jr., A. “Compact sensor combining digital speckle pattern interferometry and the hole-drilling technique to measure non-uniform residual stress fields,” Opt. Eng. 52 (10), 101905.1-101905.8 (2013).
[7] Albertazzi Jr, A.; Zanini, F. ; Viotti, M. R. ; Veiga, C. L. N. “Residual stresses measurement by the hole-drilling technique and DSPI using the integral method with displacement coefficients”. In: 5th International Symposium on Experimental Mechanics e 9th Symposium on Optics in Industry, 2015, v. 1. p. 1-7.
[8] Schajer, G. S., “Measurement of Non-Uniform Residual Stresses Using the Hole-Drilling Method. Part I – Stress Calculation Procedures”, J. Eng. Mater. Technol.. 1988; 110(4):338-343. doi: 10.1115/1.3226059. http://dx.doi.org/10.1115/1.3226059
[9] Pacheco, A.; Fontana, F.; Viotti, M. R. ; Veiga, C. L. N. ; Lothhammer, L. R. ; Albertazzi Jr, A. “Bending moment evaluation of a long specimen using a radial speckle pattern interferometer in combination with relaxation methods”. In: SPECKLE 2015: International Conference on Speckle Metrology, 2015, Guanajuato. SPECKLE 2015. Guanajuato: CIO, 2015. v. 1.