Measurement of Residual Stresses with Optical Techniques

• Type: Article in International Scientific Journal
• Date: 2009

Authors

Ribeiro, J (Author) Other; Monteiro, J (Author) Other; Mário Vaz (Author) FEUP; Lopes, H (Author) Other; Piloto, P (Author) Other

Journal

Title: Strain

Vol. 45

Pages: 123-130

ISSN: 0039-2103

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 15 Citations

Scopus - 18 Citations

Other information

Authenticus ID: P-003-MCG

DOI: 10.1111/j.1475-1305.2008.00421.x

Abstract (EN): The goal of this work was the development of other experimental techniques to measure residual stresses, as an alternative to the hole-drilling method with strain gauges. The proposed experimental techniques are based on the use of MoirE interferometry and in-plane electronic speckle pattern interferometry (ESPI). Both are field techniques allowing the assessment of in-plane displacements without contact and high resolution. Grating replication techniques were developed to record high-quality diffraction gratings onto the specimen's surfaces. An optical set-up of laser interferometry was developed to generate the master grating (virtual). An in-plane ESPI set-up was also designed and implemented to measure displacements in one direction. The stress relaxation was promoted by the blind hole-drilling and the obtained fringe patterns (MoirE and speckle) were video-recorded. Image processing techniques were applied to assess the in-plane strain field. A finite-element code (ansys (R)) was used to simulate the stress relaxation process, whose values were compared with the experimental data, and to calculate the hole-drilling calibration constants.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8