Material characterization and damage assessment of an AA5352 aluminium alloy using digital image correlation

The emergence of reliable material characterization techniques in automotive and aeronautical industries, in particular sheet metal forming, promises to underpin a novel advance in materials research. In this regard, 5xxx series aluminium alloys deliver the largest formability range and can be deformed at room temperature. This study aims at determining the mechanical properties of the AA5352 aluminium alloy, using digital image correlation. Thus, tensile sheet specimens manufactured from the corresponding alloy are mechanically tested under a uniaxial condition and deformation fields are monitored. Considering the force/displacement response and stress/strain curves, the material Poisson’s ratio, Young’s modulus and anisotropy coefficient in the transverse direction are characterized by the experimental digital image correlation data. It intends to obtain accurate and reliable mechanical properties to be considered in the future processing analyses. Numerically, adopting the experimentally obtained material properties, the Gurson–Tvergaard–Needleman damage model is implemented using finite element method formulation to forecast the ductile fracture performance of the tested AA5352 sheet. The predicted results are then compared with the experimental digital image correlation solution verifying good agreement with the force/displacement response and the deformation fields. Overall, the acquired numerical results imply that the Gurson–Tvergaard–Needleman damage criterion is capable to render an accurate prediction upon a high stress triaxiality state.

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A digital image correlation based methodology to characterize formability in tube forming

The Journal of Strain Analysis for Engineering Design ◽

10.1177/0309324718823629 ◽

2019 ◽

Vol 54 (2) ◽

pp. 139-148 ◽

Cited By ~ 3

Author(s):

Valentino AM Cristino ◽

Joao P Magrinho ◽

Gabriel Centeno ◽

Maria Beatriz Silva ◽

Paulo AF Martins

Keyword(s):

Digital Image Correlation ◽

Digital Image ◽

Effective Strain ◽

Stress Triaxiality ◽

Image Correlation ◽

Ductile Damage ◽

Tube Forming ◽

Loading Paths ◽

A New Technique ◽

Force Displacement

This article describes a methodology to characterize the failure limits by necking and fracture, and to determine the critical value of ductile damage in tube forming. The methodology makes use of digital image correlation, thickness measurements and force–displacement evolutions to obtain the strain loading paths and the strain values at the onsets of failure by necking and fracture. The onset of failure by necking is determined by a new technique that combines the strain and force–displacement evolutions whereas the fracture strains at the cracked regions of the tubes are obtained by a similar technique utilized by the authors in sheet metal forming. Transformation of the strain loading paths from principal strain space into the space of effective strain versus stress-triaxiality allows determining the critical experimental value of ductile damage at the onset of failure by necking. The methodology is applied to tube expansion with circular, elliptical and square cross-section punches and results confirm its importance and helpfulness for researchers and engineers involved in the development and optimization of industrial tube forming processes.

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Intermediate Strain Rate Material Characterization with Digital Image Correlation

Journal of Visualized Experiments ◽

10.3791/59168 ◽

2019 ◽

Author(s):

Meysam Rahmat ◽

David Backman ◽

Richard Desnoyers

Keyword(s):

Digital Image Correlation ◽

Strain Rate ◽

Digital Image ◽

Material Characterization ◽

Image Correlation ◽

Intermediate Strain Rate

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Application of digital image correlation to determine the mechanical properties of biomaterials

Engineering Mechanics 2018 ◽

10.21495/91-8-277 ◽

2018 ◽

Keyword(s):

Mechanical Properties ◽

Digital Image Correlation ◽

Digital Image ◽

Image Correlation

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Measurement of mechanical properties of carp scales based on digital image correlation method

Journal of Physics Conference Series ◽

10.1088/1742-6596/1605/1/012107 ◽

2020 ◽

Vol 1605 ◽

pp. 012107

Author(s):

Zhongnan Fu ◽

Wanlong Ma ◽

Tiantian Zhu ◽

Pei Ye ◽

Guihua Li

Keyword(s):

Mechanical Properties ◽

Digital Image Correlation ◽

Digital Image ◽

Correlation Method ◽

Image Correlation ◽

Digital Image Correlation Method

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Local Elasto-Plastic Identification of the Behaviour of Friction Stir Welds with the Virtual Fields Method

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.70.135 ◽

2011 ◽

Vol 70 ◽

pp. 135-140 ◽

Cited By ~ 2

Author(s):

G. Le Louëdec ◽

M.A. Sutton ◽

Fabrice Pierron

Keyword(s):

Mechanical Properties ◽

Digital Image Correlation ◽

Digital Image ◽

High Speed ◽

Weld Zone ◽

Spatial Variations ◽

Image Correlation ◽

Virtual Fields Method ◽

Full Field ◽

Friction Stir

Welding is one of the most popular joining technologies in industry. Depending on the materials to be joined, the geometry of the parts and the number of parts to be joined, there is a wide variety of methods that can be used. These joining techniques share a common feature: the material in the weld zone experiences different thermo-mechanical history, resulting in significant variations in material microstructure and spatial heterogeneity in mechanical properties. To optimize the joining process, or to refine the design of welded structures, it is necessary to identify the local mechanical properties within the different regions of the weld. The development of full-field kinematic measurements (digital image correlation, speckle interferometry, etc.) helps to shed a new light on this problem. The large amount of experimental information attained with these methods makes it possible to visualize the spatial distribution of strain on the specimen surface. Full-field kinematic measurements provide more information regarding the spatial variations in material behaviour. As a consequence, it is now possible to quantify the spatial variations in mechanical properties within the weld region through a properly constructed inverse analysis procedure. High speed tensile tests have been performed on FSW aluminium welds. The test was performed on an MTS machine at a cross-head speed of up to 76 mm/s. Displacement fields were measured across the specimen by coupling digital image correlation with a high-speed camera (Phantom V7.1) taking 1000 frames per second. Then, through the use of the virtual fields method it is possible to retrieve the mechanical parameters of the different areas of the weld from the strain field and the loading. The elastic parameters (Young’s modulus and Poisson’s ratio) are supposed to be constant through the weld. Their identification was carried out using the virtual fields method in elasticity using the data of the early stage of the experiment. Assuming that the mechanical properties (elastic and plastic) of the weld are constant through the thickness, the plastic parameters were identified on small sections through the specimen, using a simple linear hardening model. This method leads to a discrete identification of the evolution of the mechanical properties through the weld. It allows the understanding of the slight variations of yield stress and hardening due to the complexity of the welding process.

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