Residual Stresses Measurement and Inner Geometry Inspection of Pipelines by Optical Methods

Albertazzi, Armando; Viotti, Matı́as R.; Buschinelli, Pedro; Hoffmann, Allan; Kapp, Walter A.

doi:10.1007/978-1-4614-0225-1_1

Cited by 5 publications

(2 citation statements)

References 8 publications

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“…In this respect, the response time of less than 1s can be compatible with real-time operation for a plant with a defect rate < 1defect/s [14]. We remark here that most processing time is devoted to features identification that can be drastically reduced using modern parallel computing architectures, essentially based on CUDA architectures [64,65].…”

Section: Discussionmentioning

confidence: 99%

Automatic Defect Classification on a Production Line

Borghese

Fomasi

2015

Intell Ind Syst

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We describe here a novel defect classification system that works in real-time on the images of material running on the production line, provided by a video-inspection module. The classifier is constituted of a two-levels hierarchical architecture: a set of adequate features are extracted from the image first; the defect type is then identified from them. Statistical analysis allows greatly reducing the number of features, leaving only the most significant ones. A particular version of multi-class boosting has been developed for labeling: differently from its original version, it accepts only one label for each image, the true one, and does not require the rank for the other classes. Nevertheless, the classifier is able to produce a valid rank of the defect with respect to all the classes, information that can be used to achieve an identification rate of the dangerous defects very close to 100 % on a real data set.

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Section: Discussionmentioning

confidence: 99%

Automatic Defect Classification on a Production Line

Borghese

Fomasi

2015

Intell Ind Syst

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“…Digital speckle pattern interferometry (DSPI) and electronic speckle pattern interferometry (ESPI) are the two basic approaches of illuminating the surface either through a single illumination beam or double illumination beams [15,22,23]. Typically, single illumination is mainly suitable for measurements of out-of-plane displacements where the interference is constructed by superimposing a reference illumination on the surface illumination, which can be directed to the camera sensor or to an auxiliary surface.…”

Section: Introductionmentioning

confidence: 99%

Comparison Between Surface and Near-Surface Residual Stress Measurement Techniques Using a Standard Four-Point-Bend Specimen

Rahimi

Violatos

2021

Exp Mech

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Background Determination of near-surface residual stresses is challenging for the available measurement techniques due to their limitations. These are often either beyond reach or associated with significant uncertainties. Objective This study describes a critical comparison between three methods of surface and near-surface residual stress measurements, including x-ray diffraction (XRD) and two incremental central hole-drilling techniques one based on strain-gauge rosette and the other based on electronic speckle pattern interferometry (ESPI). Methods These measurements were performed on standard four-point-bend beams of steel loaded to known nominal stresses, according to the ASTM standard. These were to evaluate the sensitivity of different techniques to the variation in the nominal stress, and their associated uncertainties. Results The XRD data showed very good correlations with the surface nominal stress, and with superb repeatability and small uncertainties. The results of the ESPI based hole-drilling technique were also in a good agreement with the XRD data and the expected nominal stress. However, those obtained by the strain gauge rosette based hole-drilling technique were not matching well with the data obtained by the other techniques nor with the nominal stress. This was found to be due to the generation of extensive compressive residual stress during surface preparation for strain gauge installation. Conclusion The ESPI method is proven to be the most suitable hole-drilling technique for measuring near-surface residual stresses within distances close to the surface that are beyond the penetration depth of x-ray and below the resolution of the strain gauge rosette based hole-drilling method.

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A Short Survey on Residual Stress Measurements by HDM and ESPI

Pappalettere

2017

Advancement of Optical Methods in Experimental Mechanics, Volume 3

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Residual Stresses Measurement and Inner Geometry Inspection of Pipelines by Optical Methods

Cited by 5 publications

References 8 publications

Automatic Defect Classification on a Production Line

Automatic Defect Classification on a Production Line

Comparison Between Surface and Near-Surface Residual Stress Measurement Techniques Using a Standard Four-Point-Bend Specimen

A Short Survey on Residual Stress Measurements by HDM and ESPI

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