Single-camera high-speed stereo-digital image correlation for full-field vibration measurement

2017 ◽  
Vol 94 ◽  
pp. 374-383 ◽  
Author(s):  
Liping Yu ◽  
Bing Pan
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
High Speed ◽  
Image Correlation ◽  
Vibration Measurement ◽  
Single Camera ◽  
Full Field ◽  
Stereo Digital Image Correlation

scholarly journals A Simple and Practical Single-Camera Stereo-Digital Image Correlation Using a Color Camera and X-Cube Prism

Sensors ◽  
2019 ◽  
Vol 19 (21) ◽  
pp. 4726 ◽  
Author(s):  
Bo Dong ◽  
Fancang Zeng ◽  
Bing Pan
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
High Speed ◽  
Image Correlation ◽  
Single Camera ◽  
Full Field ◽  
3D Shape ◽  
Stereo Digital Image Correlation ◽  
Deformation Measurements ◽  
Dic Technique

A simple and practical full-frame single-camera stereo-digital image correlation (stereo-DIC) technique for three-dimensional (3D) shape, displacement, and deformation measurements is proposed. The technique uses a compact X-cube prism-based color separation device and a color camera to capture images of blue and red colors from different optical paths, and then extracts the surface 3D shape and deformation information of a test sample by processing the captured two sub-channel color images using regular stereo-DIC algorithm. Compared with the existing full-frame single-camera stereo-DICs, the proposed one eliminates the need for a beam splitter and two bandpass filters to capture images, and offers more simple, compact, and easy-to-use optical arrangement. This novel single-camera stereo-DIC technique was validated by a series of baseline experiments involving 3D surface reconstructions, translation tests, and full-field deformation measurements, which provide a new flexible and practical avenue for measuring surface 3D shape and deformation, particularly in microscopic and high-speed applications.

scholarly journals High-Speed X-ray Stereo Digital Image Correlation for Fluid-Structure Interactions in a Shock Tube

2020 ◽  
Author(s):  
Jeremy James ◽  
Elizabeth M. Jones ◽  
Enrico C. Quintana ◽  
Kyle P. Lynch ◽  
Benjamin R. Halls ◽  
...  
Keyword(s):  
Digital Image Correlation ◽  
Shock Tube ◽  
Digital Image ◽  
High Speed ◽  
Image Correlation ◽  
Fluid Structure Interactions ◽  
Fluid Structure ◽  
X Ray ◽  
Stereo Digital Image Correlation

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

2011 ◽  
Vol 70 ◽  
pp. 135-140 ◽  
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.

Measurement of Transient Dynamic Response of Circuit Boards of a Handheld Device During Drop Using 3D Digital Image Correlation

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
S. B. Park ◽  
Chirag Shah ◽  
Jae B. Kwak ◽  
Changsoo Jang ◽  
Soonwan Chung ◽  
...  
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
High Speed ◽  
Image Correlation ◽  
Impact Response ◽  
Experimental Methodology ◽  
Full Field ◽  
Handheld Device ◽  
3D Digital Image Correlation ◽  
The Impact

In this work, a new experimental methodology for analyzing the drop impact response is assessed using a pair of high-speed digital cameras and 3D digital image correlation software. Two different test boards are subjected to Joint Electron Device Engineering Council (JEDEC) standard free-fall impact conditions of half-sine pulse of 1500 G in magnitude and 0.5 ms in duration. The drop is monitored using a pair of synchronized high-speed cameras at a rate of up to 15,000 frames per second. The acquired images are subsequently analyzed to give full-field dynamic deformation, shape, and strain over the entire board during and after impact. To validate this new methodology for analyzing the impact response, the in-plane strain as well as the out-of-plane acceleration at selected locations were measured simultaneously during the drop using strain gauge and accelerometers and were compared with those obtained using high-speed cameras and 3D digital image correlation presented in this paper. Comparison reveals excellent correlation of the transient behavior of the board during impact and confirms the feasibility of using the full-field measurement technique used in this study.

Digital Speckle Projection for Vibration Measurement by Applying Digital Image Correlation Method

2006 ◽  
Vol 326-328 ◽  
pp. 99-102 ◽  
Author(s):  
Fu Jun Yang ◽  
Xiao Yuan He
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
High Speed ◽  
Speckle Pattern ◽  
Plane Deformation ◽  
Correlation Method ◽  
Image Correlation ◽  
Vibration Measurement ◽  
Digital Image Correlation Method ◽  
Digital Speckle

Digital image correlation method (DICM) is described as a robust in-plane deformation measuring method due to its simple optical setup and the insensitivity against ambient noise. Based on DICM, digital speckle projection has been developed for shape measurement. This paper explores the possibilities for vibration analysis using digital speckle projection together with DICM. A digital speckle pattern, generated by computer, is projected on an object surface using an LCD projector. Then the dynamic deformation modulated speckle images are captured by a high-speed CCD camera and saved in the computer. By using the self-developed temporal sequence digital images correlation algorithm, the deformation and vibration mode can be analyzed quantitatively. The proposed method avoids using stroboscopic or laser illumination and simplifies the experimental setup for vibration measurement, while it is time-consuming thanks to calculating a large amount of correlation coefficients. The experimental performance on a harmonic-vibrating cantilever beam well demonstrates the validity of the new method.

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