Hydrostatic Implosion of GFRP Composite Tubes Studied by Digital Image Correlation

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Michael Pinto ◽  
Sachin Gupta ◽  
Arun Shukla
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
High Speed ◽  
Dynamic Pressure ◽  
Three Dimensional ◽  
Image Correlation ◽  
High Speed Photography ◽  
Damage Potential ◽  
Full Field ◽  
Pressure Transducers

The mechanisms and pressure fields associated with the hydrostatic implosion of glass fiber reinforced polymer (GFRP) tubes with varying reinforcement are investigated using high-speed photography. Experiments are conducted in a large pressure vessel, designed to provide constant hydrostatic pressure throughout collapse. Three-dimensional (3D) digital image correlation (DIC) is used to capture full-field displacements, and dynamic pressure transducers measure the pressure pulse generated by the collapse. Results show that braided GFRP tubes release pressure waves with significantly greater impulse upon collapse as compared to filament-wound tubes, increasing their damage potential.

scholarly journals RGB Colour Encoding Improvement for Three-Dimensional Shapes and Displacement Measurement Using the Integration of Fringe Projection and Digital Image Correlation

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 3130 ◽  
Author(s):  
Luis Felipe-Sesé ◽  
Ángel Molina-Viedma ◽  
Elías López-Alba ◽  
Francisco Díaz
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
High Speed ◽  
Low Cost ◽  
Three Dimensional ◽  
Displacement Measurement ◽  
Image Correlation ◽  
Fringe Projection ◽  
Colour Pattern ◽  
Full Field

Three-dimensional digital image correlation (3D-DIC) has become the most popular full-field optical technique for measuring 3D shapes and displacements in experimental mechanics. The integration of fringe projection (FP) and two-dimensional digital image correlation (FP + DIC) has been recently established as an intelligent low-cost alternative to 3D-DIC, overcoming the drawbacks of a stereoscopic system. Its experimentation is based on the colour encoding of the characterized fringe and speckle patterns required for FP and DIC implementation, respectively. In the present work, innovations in experimentation using FP + DIC for more accurate results are presented. Specifically, they are based on the improvement of the colour pattern encoding. To achieve this, in this work, a multisensor camera and/or laser structural illumination were employed. Both alternatives are analysed and evaluated. Results show that improvements both in three-dimensional and in-plane displacement are obtained with the proposed alternatives. Nonetheless, multisensor high-speed cameras are uncommon, and laser structural illumination is established as an important improvement when low uncertainty is required for 2D-displacement measurement. Hence, the uncertainty has been demonstrated to be reduced by up to 50% compared with results obtained in previous experimental approaches of FP + DIC.

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.

Development of Digital Imagine Correlation (DIC) Method for Three-Dimensional Rugged Surface of Construction Material

2011 ◽  
Vol 243-249 ◽  
pp. 5907-5910 ◽  
Author(s):  
Ming Hsiang Shih ◽  
Wen Pei Sung ◽  
Darius Bacinskas
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
High Speed ◽  
Construction Material ◽  
Three Dimensional ◽  
Plaster Cast ◽  
Image Correlation ◽  
Real Surface ◽  
Facial Mask ◽  
Rugged Surface

Digital Image Correlation, DIC method is developed a low-cost digital image correlation coefficient method based on advanced digital cameras and high-speed computers. Traditionally, two or more cameras are widely applied for conducting 3-D monitoring. There are numerous parameters need to be accurately calibrated. Therefore, the results of 3-D accuracy are worse than that of 2-D accuracy. The feasibility of a single camera to collect image to analyze the three-dimensional rugged surface of material is proposed in this study. A three-dimensional facial mask-like human makeup test and plaster cast are used to test. The test results reveal that the coordinate error between these two photos of the three-dimensional facial mask-like human makeup test is only 0.002mm and the absolute displacement, rotate on z-axis, strain on z-axis and von Mises strain of analysis results are extremely close to the real surface plaster cast.

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.

scholarly journals Key aspects of digital image correlation in impact tests of reinforced concrete beams

2019 ◽  
Author(s):  
Morgan Johansson ◽  
Rasmus Rempling ◽  
Gonzalo S. D. de Ulzurrun ◽  
Carlos Zanuy
Keyword(s):  
Reinforced Concrete ◽  
Digital Image Correlation ◽  
Digital Image ◽  
High Speed ◽  
Concrete Beams ◽  
Computational Cost ◽  
Reinforced Concrete Beams ◽  
Image Correlation ◽  
High Speed Photography ◽  
Key Aspects

<p>This paper studies 2-D high speed photography combined with digital image correlation (DIC) applied to experimental research of reinforced concrete beams at moderate loading rates. The aim of the present research is to understand the influence of 2-D DIC set-up parameters in the results. Drop-weight tests have been completed in 1180 × 100 × 100 mm longitudinally reinforced concrete beams. The study has confirmed results sensitivity to image subdivision and mesh properties. While smaller subdivision sizes allow to obtain results nearby boundaries, being more suitable to study local effects, larger sizes enhance computational cost, increase mesh stability and accuracy. A discussion of key aspects of 2-D DIC for measuring different parameters (such as acceleration, displacements, strains and strain-rate) is presented along this paper.</p>

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