Application of Digital Image Correlation technique to Erichsen Cupping Test

Aydın, Murat; Wu, Xin; Çetinkaya, Kerim; Yaşar, Mustafa; Kadi, Ibrahim

doi:10.1016/j.jestch.2018.06.004

Cited by 16 publications

(16 citation statements)

References 31 publications

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“…The experiment was performed employing an TSM–100 machine with a maximum load capacity of

, and the test samples were tested at room temperature with a strain rate of 0.001

, as shown in Figure 3 a. The standard GOM–ARAMIS technique was adopted for investigating the local deformations in the samples using the recorded digital images during the tensile test till the rupture [ 24 , 25 , 26 ]. The major strain in terms of technical strain (%) in the test sample was measured using the digital image correlation (DIC) system (Aramis) just before and after the rupture, as illustrated in Figure 3 c. The average major strain extraction from the test sample along the longitudinal axis up to fracture was compared against the strain estimated based on the gauge length before and after the test to ensure that the calculation was done correctly.…”

Section: Methodsmentioning

confidence: 99%

“…Compared to conventional measurement systems such as tensile test equipped with the mechanical extensometer, strain measurement probes, and 3D coordinates estimation instruments, the DIC technique is extensively employed to measure the large deformation and strains because of its ease of convenience during the forming experiments. However, the sample’s surface must be prepared with a proper random speckle pattern to achieve more accurate results; otherwise, it might lead to wrong material data estimation [ 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ]. The authors, wang et al [ 32 ], Minsso Kim et al [ 33 ], Kupke et al [ 34 ], and Szabolcs Szalai et al [ 35 ], have successfully implemented the DIC method for the tensile test to estimate the material properties.…”

Section: Introductionmentioning

confidence: 99%

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Experimental and Numerical Investigation of AA5052-H32 Al Alloy with U-Profile in Cold Roll Forming

2021

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The cold roll forming process is broadly used to produce a specific shape of cold-roll formed products for their applications in automobiles, aerospace, shipbuilding, and construction sectors. Moreover, a proper selection of strip thickness and forming speed to avoid fracture is most important for manufacturing a quality product. This research aims to investigate the presence of longitudinal bow, the reason behind flange height deviation, spring-back, and identification of thinning location in the cold roll-forming of symmetrical short U-profile sheets. A room temperature tensile test is performed for the commercially available AA5052–H32 Al alloy sheets using Digital Image Correlation (DIC) technique, which allows complete displacement and strain data information at each time-step. The material properties are estimated from the digital images using correlation software for tested samples; the plastic strain ratios are also calculated from samples at 0°, 45°, and 90° to the rolling direction. The tested sample’s surface morphology and the elemental analysis are conducted using scanning electron microscopy (SEM) method and energy-dispersive X-ray spectroscopy (EDS) analytical technique combined with element mapping analysis, respectively. The cold roll forming experiments are systematically carried out, and then finite element analysis is utilized to correlate the experiment with the model. The performed cold roll forming numerical model outcome indicates a good agreement with the experimental measurements. Overall, the presented longitudinal strain was observed to influence the geometry profile. The spring-back is also noticed at the profile tail end and is more pronounced at high forming speed with lower strip thickness. Conversely, while the forming speed is varied, the strain and stress variations are observed to be insignificant, and the similar results also are recognized for the thinning behavior.

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“…The experiment was performed employing an TSM–100 machine with a maximum load capacity of

, and the test samples were tested at room temperature with a strain rate of 0.001

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Experimental and Numerical Investigation of AA5052-H32 Al Alloy with U-Profile in Cold Roll Forming

2021

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“…Optical techniques such as digital image correlation (DIC) and laser speckle interferometry have been used to monitor the dome heights at which failure occurs for different sheet thicknesses (steel and aluminium) and to evaluate the necking behaviour [16][17][18]. Models have examined strains at certain IEs to determine a failure criterion for sheet metal neglecting the presence of a coating [18][19][20][21].…”

Section: Introductionmentioning

confidence: 99%

Quantification of coating surface strains in Erichsen cupping tests

et al. 2019

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Thermosetting polyester-based coatings are used to produce pre-painted metal in the coil coating industry. The coated steel sheet is formed into white goods and architectural cladding, which involves large deformations of the metal and results in large strains in the coating. The Erichsen cupping test is a standard method used to assess the formability, ductility and adhesion of coatings, which induces similar strains to those experienced during forming. It is a qualitative and robust quality control method, but the behaviour of coatings during the test has never been previously studied quantitatively. Failure of coatings on sheet metal during forming is a strain-governed process, so understanding the behaviour of a coating in the Erichsen cupping test will allow the formability, material properties and chemical structure of the polymer to be linked more closely, enabling the development of better coatings. A finite element model has been developed to calculate the coating surface strains for any level of indentation during the test and has been validated using the surface strains during cupping measured by digital image correlation. A master curve of the maximum strain versus the indentation depth (Erichsen index) has been determined. This allows the strain to failure of the coating on a substrate, a critical material property which is otherwise difficult and laborious to obtain, to be simply determined from the Erichsen test for the first time. The relationship between the Erichsen index and maximum surface strain presented here enables users to obtain this material property both from future tests and from the results of historic tests (as many coating suppliers and users have extensive databases of Erichsen test results stretching back many years). This novel framework provides a quantitative method to analyse the performance of coatings used in the coil industry, redeveloping a century-old technique.

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“…The number of cameras has to be increased and positioned to take the images from different angles. The same analysis methodology is applied and the computational time does not increase as much as in other analysis techniques, such as 3D FEM [38,39]. The methodology is not only applicable to 3D objects, but also to objects in motion [24,40] and objects subjected to large deformations [41,42].…”

Section: Introductionmentioning

confidence: 99%

2D–3D Digital Image Correlation Comparative Analysis for Indentation Process

et al. 2019

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Nowadays, localized forming operations, such as incremental forming processes, are being developed as an alternative to conventional machining or forming techniques. An indentation process is the main action that takes places in these forming activities, allowing small, localized deformations. It is essential to have the knowledge of the material behavior under the punch and the transmitted forces to achieve correct control of the entire procedure. This paper presents the work carried out with the digital image correlation (DIC) technique applied to the study of the material flow that takes place under an indentation process. The material flow analysis is performed under 2D and 3D conditions, establishing the methodology for the calibration and implementation for each alternative. Two-dimensional DIC has been proven to be a satisfactory technique compared with the 3D method, showing results in good agreement with experimental tests and models developed by the finite element method. Notwithstanding, part of the indented material flows under the punch, emerging on the front surface and generating a dead zone that can only be addressed with a 3D technique. So, the main objective is to carry out a comparison between the 2D and 3D techniques to identify if the 3D application could be mandatory for this type of process. Also, a 2D-3D mix analysis is proposed for study cases in which it is necessary to know the material flow in that specific area of the workpiece.

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Application of Digital Image Correlation technique to Erichsen Cupping Test

Cited by 16 publications

References 31 publications

Experimental and Numerical Investigation of AA5052-H32 Al Alloy with U-Profile in Cold Roll Forming

Experimental and Numerical Investigation of AA5052-H32 Al Alloy with U-Profile in Cold Roll Forming

Quantification of coating surface strains in Erichsen cupping tests

2D–3D Digital Image Correlation Comparative Analysis for Indentation Process

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