scholarly journals Preliminary Experimental and Numerical Study of Metal Element with Notches Reinforced by Composite Materials

2021 ◽  
Vol 5 (5) ◽  
pp. 134
Author(s):  
Paweł J. Romanowicz ◽  
Bogdan Szybiński ◽  
Mateusz Wygoda
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Numerical Study ◽  
Correlation Method ◽  
Industrial Applications ◽  
Experimental Results ◽  
Image Correlation ◽  
Stress Concentrations ◽  
Element Analysis ◽  
Wide Range

The presented study is related to the application of the composite overlays used in order to decrease the effect of the stress concentrations around the cut-outs in structural metal elements. The proposed approach with the application of the digital image correlation extends the recently presented studies. Such structural elements with openings of various shapes have been accommodated for a wide range of industrial applications. These structures exhibit certain stress concentrations which decrease their durability and strength. To restore their strength, various reinforcing overlays can be used. In the present paper, the flat panel structure without and with the composite overlays made of HEXCEL TVR 380 M12/26%/R-glass/epoxy is under the experimental and the numerical study. Particular attention is paid to the investigation of the samples with the rectangular holes, which for smooth rounded corners offer a higher durability than the samples with the circular hole of the same size. The experimental results are obtained for the bare element and are reinforced with composite overlay samples. The experimental results are obtained with the use of the Digital Image Correlation method, while the numerical results are the product of the Finite Element Analysis. In the numerical analysis, the study of the shape, size and fiber orientation in applied overlays is done. The reduction of the stress concentration observed in opening notches has confirmed the effectiveness of the overlay application. In the investigated example, the application of the square composite overlay increased the structure strength even by 25%.

scholarly journals Study on the Measurement of Laser Drilling Depth by Combining Digital Image Relationship Measurement in Aluminum

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 489
Author(s):  
Chao-Ching Ho ◽  
Guan-Hong Li
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Laser Processing ◽  
Correlation Method ◽  
Experimental Results ◽  
Image Correlation ◽  
Detection Methods ◽  
Coefficient Of Determination ◽  
Drilling Depth ◽  
Hole Depth

In this study, laser processing equipment was used to drill aluminum alloy materials and with different auxiliary mechanisms, the deformation around the holes after processing was observed. The experimental results show that, due to the high temperature generated during laser processing, a large thermal gradient causes thermal stress to be introduced into the test piece and outward expansion deformation occurs. In this study, the digital image correlation and residual stress detection methods were applied. Based on the correlation between the drilled hole depth and the hole deformation, the hole depth of the laser processing was estimated. The average coefficient of determination for all auxiliary mechanisms is 0.82. The experimental results confirm that the digital image correlation method can be used to estimate the hole depth of laser processing.

Two-Steps Digital Image Correlation and Application to Studies of Micromechanics Behavior of Coating Interface

2007 ◽  
Vol 336-338 ◽  
pp. 1810-1813
Author(s):  
Jin Long Chen ◽  
Quan Yu Liu ◽  
Yu Wen Qin ◽  
Xin Hua Ji
Keyword(s):  
Digital Image Correlation ◽  
Base Metal ◽  
Digital Image ◽  
Spline Interpolation ◽  
Compressive Strain ◽  
Correlation Method ◽  
Experimental Results ◽  
Image Correlation ◽  
Different Thickness ◽  
Better Than

In this paper, two-steps digital image correlation method is well advanced with the sub-pixel reconstruction in sub-image by utilizing the higher precision calculation of bicubic spline interpolation value method, and the accuracy of displacement is extended to better than 0.01 pixel, the strain resolution is limited to less than 0.0002 in micro-region. The experimental results show that the method of two-steps digital image correlation is an up-to-date technique to comprehensive investigations of base metal-coating composition at extremely small size scales. In the meantime, influence of crack in base metal perpendicular to interface on coating is directly observed, and the measurement of the residual compressive strain in base metal is performed according to different thickness of coatings. Lastly, the bond behavior between base metal and coating has been quantitatively analyzed, and the experimental results also prove the Ni-Lan coating is combined with base metal by toughened interface.

scholarly journals Design of a Unique Device for Residual Stresses Quantification by the Drilling Method Combining the PhotoStress and Digital Image Correlation

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 314
Author(s):  
Miroslav Pástor ◽  
Martin Hagara ◽  
Ivan Virgala ◽  
Adam Kaľavský ◽  
Alžbeta Sapietová ◽  
...  
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Experimental Testing ◽  
Digital Processing ◽  
Image Correlation ◽  
Optical Systems ◽  
Hole Drilling ◽  
Element Analysis ◽  
Thin Specimen ◽  
Comparison Of The Results

This paper presents a uniquely designed device combining the hole-drilling technique with two optical systems based on the PhotoStress and digital image correlation (DIC) method, where the digital image correlation system moves with the cutting tool. The authors aimed to verify whether the accuracy of the drilled hole according to ASTM E837-13a standard and the positioning accuracy of the device were sufficient to achieve accurate results. The experimental testing was performed on a thin specimen made from strain sensitive coating PS-1D, which allowed comparison of the results obtained by both methods. Although application of the PhotoStress method allows analysis of the strains at the edge of the cut hole, it requires a lot of experimenter’s practical skills to assess the results correctly. On the other hand, the DIC method allows digital processing of the measured data. However, the problem is not only to determine the data at the edge of the hole, the results also significantly depend on the smoothing levels used. The quantitative comparison of the results obtained was performed using finite element analysis.

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