scholarly journals Strain Evolution Measurement at the Microscale of a Dual Phase Steel Using Digital Image Correlation

2010 ◽  
Vol 24-25 ◽  
pp. 201-206 ◽  
Author(s):  
H. Ghadbeigi ◽  
C. Pinna ◽  
Steven Celotto ◽  
J.R. Yates
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Dual Phase Steel ◽  
Tensile Tests ◽  
Image Correlation ◽  
Scanning Electron Micrographs ◽  
Plastic Strains ◽  
Full Field ◽  
Loading Direction

Digital Image Correlation (DIC) together with in-situ tensile testing has been used to measure in DP1000 steel the evolution of plastic strains at the microstructure scale. Interrupted tensile tests were performed on specially designed samples and scanning-electron micrographs were taken at regular applied strain intervals. Patterns defined by the microstructural features of the material have been used for the correlation carried out using LAVision software. The full field strain maps produced by DIC show a progressive localisation of deformation into bands at about 45o with respect to the loading direction. Plastic strains as high as 130% have been measured within the ferrite phase.

scholarly journals Robust Filtering Options for Higher-Order Strain Fields Generated by Digital Image Correlation

2020 ◽  
Vol 1 (4) ◽  
pp. 174-192
Author(s):  
Nedaa Amraish ◽  
Andreas Reisinger ◽  
Dieter H. Pahr
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Tensile Tests ◽  
Image Correlation ◽  
Field Strain ◽  
Strain Fields ◽  
Full Field ◽  
Low Pass ◽  
Discrete Measurement ◽  
Mean Filtering

Digital image correlation (DIC) systems have been used in many engineering fields to obtain surface full-field strain distribution. However, noise affects the accuracy and precision of the measurements due to many factors. The aim of this study was to find out how different filtering options; namely, simple mean filtering, Gaussian mean filtering and Gaussian low-pass filtering (LPF), reduce noise while maintaining the full-field information based on constant, linear and quadratic strain fields. Investigations are done in two steps. First, linear and quadratic strain fields with and without noise are simulated and projected to discrete measurement points which build up strain window sizes consisting of 6×5, 12×11, and 26×17 points. Optimal filter sizes are computed for each filter strategy, strain field type, and strain windows size, with minimal impairment of the signal information. Second, these filter sizes are used to filter full-field strain distributions of steel samples under tensile tests by using an ARAMIS DIC system to show their practical applicability. Results for the first part show that for a typical 12×11 strain window, simple mean filtering achieves an error reduction of 66–69%, Gaussian mean filtering of 72–75%, and Gaussian LPF of 66–69%. If optimized filters are used for DIC measurements on steel samples, the total strain error can be reduced from initial 240−300 μstrain to 100–150 μstrain. In conclusion, the noise-floor of DIC signals is considerable and the preferable filters were a simple mean with s*¯ = 2, a Gaussian mean with σ*¯ = 1.7, and a Gaussian LPF with D0*¯ = 2.5 in the examined cases.

scholarly journals Damage investigation in A319 aluminum alloy by digital image correlation during in-situ tensile tests

2016 ◽  
Vol 2 ◽  
pp. 3415-3422 ◽  
Author(s):  
Zaidao Li ◽  
Nathalie Limodin ◽  
Amina Tandjaoui ◽  
Philippe Quaegebeur ◽  
Jean-François Witz ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Digital Image Correlation ◽  
Digital Image ◽  
Tensile Tests ◽  
Image Correlation ◽  
Damage Investigation

scholarly journals Brief communication: Full-field deformation measurement for uniaxial compression of sea ice by using the digital image correlation method

2019 ◽  
Author(s):  
Anliang Wang ◽  
Zhijun Wei ◽  
Xiaodong Chen ◽  
Shunying Ji ◽  
Yu Liu ◽  
...  
Keyword(s):  
Digital Image Correlation ◽  
Sea Ice ◽  
Uniaxial Compression ◽  
Digital Image ◽  
Correlation Method ◽  
Nonlinear Behavior ◽  
Image Correlation ◽  
Mechanical Behaviors ◽  
Full Field

Abstract. We took advantage of digital image correlation to measure the full-field deformation of sea ice in a uniaxial compression experiment in situ. The characteristics of failure mode, nonlinear behavior and crack propagation are all captured by the strain field of specimens. To our knowledge, this is the first attempt to experimentally capture sequential full-field deformations in the mechanical properties of sea ice. This achievement will extend the ability to further explore the complex mechanical behaviors of sea ice.

Buckling Measurement of Cylindrical Shells by Digital Image Correlation Method

2013 ◽  
Author(s):  
Tzu-Yu Kuo ◽  
Wei-Chung Wang ◽  
Chun-I Chu ◽  
Jia-He Chen ◽  
Te-Heng Hung ◽  
...  
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Strain Measurement ◽  
Cylindrical Shells ◽  
Compressive Load ◽  
Correlation Method ◽  
Tensile Tests ◽  
Image Correlation ◽  
Strain Gages ◽  
Full Field

In this study, deformation of cylindrical shells under axial compressive load was studied and characterized by a noncontact detection technique, called digital image correlation (DIC). As opposed to commonly used strain gages for measuring structure strains at specific points, the DIC method can render not only 2D but also 3D full-field measurements for strain as well as structure deformation. The accuracy of strain measurement obtained using the DIC method was carefully validated by following ASTM standard E8 for strain measurement using strain gages in tensile tests. The DIC technique provided convenient measurements for characterizing the buckling behaviors of defective cylindrical shell samples. This study has engineering implications for providing 3D strain and deformation analyses to ensure structure reliability and safety.

scholarly journals Traceable technique for an in situ full field in-plane measurement validation of digital image correlation

2017 ◽  
Vol 56 (3) ◽  
pp. 033101 ◽  
Author(s):  
Eszter Szigeti ◽  
Matthew Loparco ◽  
Evgeni Todorov ◽  
Shelby Wheatley ◽  
Richard J. Greene
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Image Correlation ◽  
Full Field ◽  
Measurement Validation

scholarly journals In Situ Monitoring of Additive Manufacturing Using Digital Image Correlation: A Review

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1511
Author(s):  
Filipa G. Cunha ◽  
Telmo G. Santos ◽  
José Xavier
Keyword(s):  
Additive Manufacturing ◽  
Digital Image Correlation ◽  
Digital Image ◽  
Field Measurements ◽  
In Situ Monitoring ◽  
Image Correlation ◽  
Full Field ◽  
The Impact ◽  
Am Processes

This paper is a critical review of in situ full-field measurements provided by digital image correlation (DIC) for inspecting and enhancing additive manufacturing (AM) processes. The principle of DIC is firstly recalled and its applicability during different AM processes systematically addressed. Relevant customisations of DIC in AM processes are highlighted regarding optical system, lighting and speckled pattern procedures. A perspective is given in view of the impact of in situ monitoring regarding AM processes based on target subjects concerning defect characterisation, evaluation of residual stresses, geometric distortions, strain measurements, numerical modelling validation and material characterisation. Finally, a case study on in situ measurements with DIC for wire and arc additive manufacturing (WAAM) is presented emphasizing opportunities, challenges and solutions.

Cellulosic-Biowaste Composites and Their Stress Determination Using Digital Image Correlation

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Yoonhyuk Ro ◽  
John F. Hunt ◽  
Robert E. Rowlands
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Value Added ◽  
Image Correlation ◽  
Full Field ◽  
Practical Applications ◽  
Recorded Data ◽  
Geometric Discontinuities ◽  
Measured Displacement

In addition to processing a troubling agricultural by-product and reducing demands on our landfills, prepared agro-waste composites are suitable for a variety of practical applications. However, enhancing value-added options for these agricultural by-products can necessitate ability to assess their mechanical integrity. This paper accordingly describes the preparation of a cellulosic-manure composite and demonstrates ability to determine stresses in a perforated structure of the material from measured displacement data. Processing digital image correlation (DIC) recorded displacement information with an Airy stress function gives reliable results full-field as well as at the edge of geometric discontinuities without having to differentiate the recorded data. Required constitutive properties are evaluated in situ and results are substantiated independently.

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