Correction of strain errors induced by small rigid-body motions in electronic speckle pattern interferometry measurement

Chen, Helen; Su, R.K.L.; Kwan, A.K.H.; Fok, Alex

doi:10.1080/1023697x.2013.785073

Cited by 8 publications

(4 citation statements)

References 14 publications

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“…The displacement measurement accuracy is 0.03–1 μm adjustable, and the CCD resolution is 1380 × 1035 pixels. Based on the previous research conclusions, [ 21 ] for the camera positioned 230 mm before the specimen surface, the displacement accuracy is 0.03 μm and the average strain discrepancy is about 0.01 με. The ESPI camera was fixed on a special bracket directly in front of the sample, and the lens was perpendicular to the specimen's surface.…”

Section: Experiments Preparation and Proceduresmentioning

confidence: 88%

“…After determining the interference phase before and after the deformation, the displacement u or v in the plane can be calculated [ 21 ] by formula 4:

u = \frac{normalΔ ((), x, y) \cdot λ}{4 π \sin α},

where Δ( x , y ) = ϕ ′ ( x , y ) − ϕ ( x , y ) is the phase difference before and after deformation, α is the angle of incidence of the light and λ is the wavelength of the laser resource.…”

Section: The Electronic Speckle Pattern Interferometry Technologymentioning

confidence: 99%

“…[ 20 ] Briefly, ESPI is a measurement technique that uses the electronic speckle images formed by coherent light beams to measure the surface deformation of an object. [ 21 ] Since ESPI has the characteristics of non‐contact and non‐destruction during the measurement procedure, [ 22 ] the measurement results of the development of the FPZ are more reliable. Furthermore, the use of ESPI does not require special treatment of the sample surface, making it possible to efficiently measure a large number of samples.…”

Section: Introductionmentioning

confidence: 99%

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Experimental investigation on the concrete fracture process zone using electronic speckle pattern interferometry

Huang

Chen

Sun

2021

Strain

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In order to advance the understanding of fracture failure mechanisms in concrete, a series of three‐point bend tests of pre‐notched specimens were conducted to study the characteristics of the fracture process zone. Electronic speckle pattern interferometry (ESPI) was used to determine the location and size of the cracks. The experimental results have shown that crack in the pre‐notched concrete beams will initiate when the load increases to 40% of the peak load (Pmax) and expands unstably after reaching the peak load. When the load drops to about 25% Pmax in the load drop section, a complete fracture process zone (FPZ) was developed, and the corresponding crack tip opening displacement is about 7.1 times to the critical crack tip opening displacement. The analysis of surface strain of concrete specimen showed that microcracks will initiate when the surface tensile strain of concrete reaches about 2 × 10−4; when the surface tensile strain value of concrete reaches 4 × 10−2, the FPZ will move forward; the length of the FPZ of concrete essentially remains the same in the entire fracture process, which is about 71% of the ligament height. The analysis of experimental data also shows that the size of the FPZ is not significantly affected by the cubic compressive strength of concrete. In addition, the tension‐softening curves of the specimens were finally determined by using the incremental displacement collocation method, and it is concluded that the critical width of the FPZ is related to the cubic compressive strength of the concrete.

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Section: Experiments Preparation and Proceduresmentioning

confidence: 88%

“…After determining the interference phase before and after the deformation, the displacement u or v in the plane can be calculated [ 21 ] by formula 4:

u = \frac{normalΔ ((), x, y) \cdot λ}{4 π \sin α},

Section: The Electronic Speckle Pattern Interferometry Technologymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Experimental investigation on the concrete fracture process zone using electronic speckle pattern interferometry

Huang

Chen

Sun

2021

Strain

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“…1). The principles of ESPI system can be found in Reference [8]. The technical specifications of Q300 system are listed in Table 2.…”

Section: Fig 1 Experimental Setup Of Three-point Bending Testmentioning

confidence: 99%

Study on Fracture Properties of Mortar Based on Electronic Speckle Pattern Interferometry

Chen

2017

MSF

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With high resolution, electronic speckle pattern interferometry (ESPI) technique can be useful in measuring full-filed deformation of laboratory specimens. In this study, ESPI was applied to measure the full-field displacements of mortar beam subjected to three-point bend. Load-displacement curves measured by ESPI were compared to that measured by clip gauge and LVDTs. Satisfactory agreement was observed in all the comparisons, demonstrating the effectiveness and accuracy of ESPI measurement. Furthermore, load versus crack tip opening displacement curve was obtained from ESPI results. Finally, extent of the fracture process zone and neutral axis of the mortar beam were analyzed based on full-filed displacement contour measured by ESPI.

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Advances in Speckle Metrology

Joenathan

Sirohi

Bernal

2015

The Optics Encyclopedia

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The field of speckle metrology has seen a surge in development in the past 10 years owing to advancements in digital cameras and computing power. For instance, a variety of digital speckle correlation (DSC) processes can now be performed in almost real time and therefore speckle techniques has found applications in nondestructive testing (NDT), biology, and medicine. New techniques in terms of optical arrangements and in extracting phase data have been introduced for measuring out‐of‐plane and in‐plane motions in digital speckle interferometry (DSPI) and digital speckle shear interferometry (DSSPI). DSC, DSPI, and DSSPI have also been combined to extend the range of measurements. In addition, quantitative analysis in speckle interferometry has seen a plethora of new software developments for conducting real‐time, accurate, complicated, fast, and repeatable measurements with ease. In addition, different methods to process speckle fringes have made analysis equivalent to that of classical interferometry, yet can be applied to all types of real‐world specimen.

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Correction of strain errors induced by small rigid-body motions in electronic speckle pattern interferometry measurement

Cited by 8 publications

References 14 publications

Experimental investigation on the concrete fracture process zone using electronic speckle pattern interferometry

Experimental investigation on the concrete fracture process zone using electronic speckle pattern interferometry

Study on Fracture Properties of Mortar Based on Electronic Speckle Pattern Interferometry

Advances in Speckle Metrology

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