A new method for characterizing nonlinearity in scanning probe microscopes using digital image correlation

Digital image correlation (DIC) is a method for measuring the surface displacements and displacement gradients in materials under deformation. The method has also been applied to the calculation of image distortion for scanning probe microscopy (SPM). The traditional DIC method directly uses the intensity values of compared images but does not take out-of-plane nonlinearity error into account. However, in SPM measurements, the recorded z-direction value is a sum of the real surface height of the sample and any longitudinal deformation of the piezoelectric tube. In order to improve the calculation accuracy of the displacement fields, an improved DIC method is performed here. Two new parameters related to out-of-plane error are introduced in the mathematical modeling. The in-plane displacements between two compared images are then calculated pixel by pixel, with the z-direction error accounted for. This method is tested by applying it to two pairs of atomic force microscopy (AFM) images along the fast and slow scan directions.

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A New Method for Determination of Forming Limit Diagram Based on Digital Image Correlation

10.4271/2013-01-1421 ◽

2013 ◽

Cited By ~ 6

Author(s):

Ling Zhang ◽

Jianping Lin ◽

Li Sun ◽

Chen Wang ◽

Li Wang

Keyword(s):

Digital Image Correlation ◽

Digital Image ◽

Forming Limit Diagram ◽

Image Correlation ◽

New Method ◽

Forming Limit

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Determination of deviatoric elastic strain and lattice orientation by applying digital image correlation to Laue microdiffraction images: the enhanced Laue-DIC method

Journal of Applied Crystallography ◽

10.1107/s1600576715018397 ◽

2015 ◽

Vol 48 (6) ◽

pp. 1805-1817 ◽

Cited By ~ 9

Author(s):

F. G. Zhang ◽

O. Castelnau ◽

M. Bornert ◽

J. Petit ◽

J. B. Marijon ◽

...

Keyword(s):

Digital Image Correlation ◽

Digital Image ◽

Elastic Strain ◽

Local Stress ◽

Image Correlation ◽

New Method ◽

Lattice Orientation ◽

Experimental Conditions ◽

Calibration Parameters ◽

Laue Microdiffraction

A new method of determining the deviatoric elastic strain and lattice orientation from Laue microdiffraction images is presented. Standard data treatment methods can suffer from the difficulty of precisely pinpointing the positions of diffraction peaks on two-dimensional Laue images. In a previous article, digital image correlation (DIC) was introduced for the treatment of Laue images, leading to the so-called Laue-DIC method. This performed better than the standard method in terms of the deviatoric elastic strain increment and relative rotation from one lattice to another, particularly when the shape of the Laue spots departs from regular ellipsoids. The present work intends to push forward the Laue-DIC method, aiming to determine the deviatoric elastic strain and lattice orientation, as well as the calibration parameters. The performance of this new method, named enhanced Laue-DIC, is assessed by modeling the spot displacements and accounting for random fluctuations relevant for typical experimental conditions. When the enhanced Laue-DIC method is applied to the case of anin situdeformed Si crystal, the obtained standard deviation of local stress is of the order of 1–2 MPa, while the calibration parameters are optimized to high accuracy.

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A new method to deal with the effect of subset size for digital image correlation

Optik ◽

10.1016/j.ijleo.2015.09.151 ◽

2015 ◽

Vol 126 (24) ◽

pp. 4940-4945 ◽

Cited By ~ 2

Author(s):

Zhenning Liang ◽

Bo Yin ◽

Jinqiu Mo ◽

Shigang Wang

Keyword(s):

Digital Image Correlation ◽

Digital Image ◽

Image Correlation ◽

New Method ◽

Subset Size

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Deformation Analysis of Asphalt Mixtures with Digital Image Correlation Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.831.470 ◽

2013 ◽

Vol 831 ◽

pp. 470-475

Author(s):

Kan Li ◽

Duan Yi Wang ◽

Jia Li ◽

Xu Cai

Keyword(s):

Digital Image Correlation ◽

Digital Image ◽

Correlation Method ◽

Ccd Camera ◽

Asphalt Mixtures ◽

Image Correlation ◽

New Method ◽

Deformation Analysis ◽

Digital Image Correlation Method ◽

Coarse Aggregates

Based on digital image correlation method (DICM), this paper promotes a new method for tracking the movements of coarse aggregates of asphalt mixtures. The four-point bending fatigue test is applied as the observed test. The fatigue damage process of AC-16 asphalt mixture is observed by CCD camera. Results show that the new method is able to well reflect the exact displacement of coarse aggregates under different loading repetitions. And the movement trends also reflect the influences of cracks in the specimens. Compared to the original method, the new method provides more detail movement information of different materials (aggregates and asphalt binder). This method helps to the research of asphalt mixtures in meso-scale.

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A New Method to Measure Crack Extension in Nuclear Graphite Based on Digital Image Correlation

Science and Technology of Nuclear Installations ◽

10.1155/2017/2416545 ◽

2017 ◽

Vol 2017 ◽

pp. 1-10 ◽

Cited By ~ 2

Author(s):

Shigang Lai ◽

Li Shi ◽

Alex Fok ◽

Haiyan Li ◽

Libin Sun ◽

...

Keyword(s):

Digital Image Correlation ◽

Digital Image ◽

Crack Extension ◽

Cross Correlation ◽

Threshold Value ◽

Step Function ◽

Image Correlation ◽

New Method ◽

Crack Identification ◽

Beam Specimen

Graphite components, used as moderators, reflectors, and core-support structures in a High-Temperature Gas-Cooled Reactor, play an important role in the safety of the reactor. Specifically, they provide channels for the fuel elements, control rods, and coolant flow. Fracture is the main failure mode for graphite, and breaching of the above channels by crack extension will seriously threaten the safety of a reactor. In this paper, a new method based on digital image correlation (DIC) is introduced for measuring crack extension in brittle materials. Cross-correlation of the displacements measured by DIC with a step function was employed to identify the advancing crack tip in a graphite beam specimen under three-point bending. The load-crack extension curve, which is required for analyzing the R-curve and tension softening behaviors, was obtained for this material. Furthermore, a sensitivity analysis of the threshold value employed for the cross-correlation parameter in the crack identification process was conducted. Finally, the results were verified using the finite element method.

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