Error Estimations in Digital Image Correlation Technique

Siebert, Thorsten; Becker, Thomas; Spiltthof, Karsten; Neumann, Isabell; Krupka, René

doi:10.4028/0-87849-453-7.265

Cited by 7 publications

(6 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moving on to DIC, experimental studies have defined effective procedures to calibrate DIC systems and/or to process the acquired images [ 26 , 27 , 28 , 29 ], thereby improving measurement accuracy. Unfortunately, although DIC has been demonstrated to be accurate in measuring medium-large strain levels [ 30 , 31 , 32 , 33 , 34 , 35 , 36 ], non negligible errors have been found when measuring small (<0.1% or 1000 microstrain) strain values [ 37 , 38 , 39 , 40 ], i.e., of the same order of magnitude of strain that CPCs can withstand before fracture. To the authors’ knowledge, there is only one report showing that the DIC technique has the potential to provide an accuracy level comparable to the strain gauge in measuring small strain values [ 41 ].…”

Section: Introductionmentioning

confidence: 99%

Experimentally Achievable Accuracy Using a Digital Image Correlation Technique in measuring Small-Magnitude (<0.1%) Homogeneous Strain Fields

2018

View full text Add to dashboard Cite

Measuring small-magnitude strain fields using a digital image correlation (DIC) technique is challenging, due to the noise-signal ratio in strain maps. Here, we determined the level of accuracy achievable in measuring small-magnitude (<0.1%) homogeneous strain fields. We investigated different sets of parameters for image processing and imaging pre-selection, based on single-image noise level. The trueness of DIC was assessed by comparison of Young’s modulus (E) and Poisson’s ratio (ν) with values obtained from strain gauge measurements. Repeatability was improved, on average, by 20–25% with experimentally-determined optimal parameters and image pre-selection. Despite this, the intra- and inter-specimen repeatability of strain gauge measurements was 5 and 2.5 times better than DIC, respectively. Moreover, although trueness was also improved, on average, by 30–45%, DIC consistently overestimated the two material parameters by 1.8% and 3.2% for E and ν, respectively. DIC is a suitable option to measure small-magnitude homogeneous strain fields, bearing in mind the limitations in achievable accuracy.

show abstract

Section: Introductionmentioning

confidence: 99%

Experimentally Achievable Accuracy Using a Digital Image Correlation Technique in measuring Small-Magnitude (<0.1%) Homogeneous Strain Fields

2018

View full text Add to dashboard Cite

show abstract

“…This process returns the new 3D positions of points on the specimen surface from which 3D displacement vectors are calculated. 3D-DIC is associated with two main sources of error: a correlation error and a 3D reconstruction error [15,16]. The reconstruction error is the error in the imaging system calibration.…”

Section: Introductionmentioning

confidence: 99%

“…The reconstruction error is the error in the imaging system calibration. It is mainly a function of the camera positioning (stereo-angle) and calibration, and the objective focal length [15,16]. …”

Section: Introductionmentioning

confidence: 99%

A comparison of 2D and 3D digital image correlation for a membrane under inflation

Murienne

Nguyen

2016

Optics and Lasers in Engineering

View full text Add to dashboard Cite

Three-dimensional (3D) digital image correlation (DIC) is becoming widely used to characterize the behavior of structures undergoing 3D deformations. However, the use of 3D-DIC can be challenging under certain conditions, such as high magnification, and therefore small depth of field, or a highly controlled environment with limited access for two-angled cameras. The purpose of this study is to compare 2D-DIC and 3D-DIC for the same inflation experiment and evaluate whether 2D-DIC can be used when conditions discourage the use of a stereo-vision system. A latex membrane was inflated vertically to 5.41 kPa (reference pressure), then to 7.87 kPa (deformed pressure). A two-camera stereo-vision system acquired top-down images of the membrane, while a single camera system simultaneously recorded images of the membrane in profile. 2D-DIC and 3D-DIC were used to calculate horizontal (in the membrane plane) and vertical (out of the membrane plane) displacements, and meridional strain. Under static conditions, the baseline uncertainty in horizontal displacement and strain were smaller for 3D-DIC than 2D-DIC. However, the opposite was observed for the vertical displacement, for which 2D-DIC had a smaller baseline uncertainty. The baseline absolute error in vertical displacement and strain were similar for both DIC methods, but it was larger for 2D-DIC than 3D-DIC for the horizontal displacement. Under inflation, the variability in the measurements were larger than under static conditions for both DIC methods. 2D-DIC showed a smaller variability in displacements than 3D-DIC, especially for the vertical displacement, but a similar strain uncertainty. The absolute difference in the average displacements and strain between 3D-DIC and 2D-DIC were in the range of the 3D-DIC variability. Those findings suggest that 2D-DIC might be used as an alternative to 3D-DIC to study the inflation response of materials under certain conditions.

show abstract

“…If these conditions are not fulfilled, also a small deviation can cause a significant error in the evaluation process, if the camera is located pretty close to the model, as it is in this case. Appropriate attention should be paid to correlation errors, which increase with a decreasing facet size [15][16][17].…”

Section: Stress Analysis Using Digital Image Correlation (Dic)mentioning

confidence: 99%

The Use of Optical Methods in the Analysis of the Areas with Stress Concentration

Pástor

Frankovský

Hagara

et al. 2018

Strojnícky Časopis - Journal of Mechanical Engineering

View full text Add to dashboard Cite

Anchoring parts of technical systems are often damaged due to the heavy forces acting on these systems during their operation. For that reason, various modifications are suggested and created on the anchoring screws, which should help to reduce the mechanical stress values in a place of the first load-bearing thread of a female screw. For the determination of stress fields on the surface of a plane model of a threaded joint, two non-contact optical methods were used – conventional transmission photoelasticimetry and modern digital image correlation.

show abstract

Error Estimations in Digital Image Correlation Technique

Cited by 7 publications

References 0 publications

Experimentally Achievable Accuracy Using a Digital Image Correlation Technique in measuring Small-Magnitude (<0.1%) Homogeneous Strain Fields

Experimentally Achievable Accuracy Using a Digital Image Correlation Technique in measuring Small-Magnitude (<0.1%) Homogeneous Strain Fields

A comparison of 2D and 3D digital image correlation for a membrane under inflation

The Use of Optical Methods in the Analysis of the Areas with Stress Concentration

Contact Info

Product

Resources

About