Deformation and Failure of Pre-Notched Thin Metal Plates Subjected to Confined Blast Loading

2015 ◽  
Vol 782 ◽  
pp. 49-58
Author(s):  
Han Liu ◽  
Peng Wan Chen ◽  
Bao Qiao Guo ◽  
Shao Long Zhang ◽  
Hai Bo Liu ◽  
...  
Keyword(s):  
High Speed ◽  
Dynamic Deformation ◽  
Blast Loading ◽  
Thin Metal ◽  
Image Correlation ◽  
Deformation And Failure ◽  
Full Field ◽  
3D Digital Image Correlation ◽  
Metal Plates ◽  
Dic Technique

In this paper, the dynamic deformation and rupture of pre-notched thin metal plates subjected to confined blast loading were investigated. The thin copper plates with cross-shape pre-notch were clamped on the end of a confined cylinder vessel by a cover flange. An explosive charge with a mass of 4g was detonated in the vessel center to generate blast load acting on the metal plates. The images of metal plates were recorded by two high-speed cameras. The displacement and strain fields during the deformation and rupture process were measured by using 3D digital image correlation (3D DIC). The effects of pre-notches on the dynamic deformation and rupture of thin metal plates were analyzed. The microstructure of fracture surface was examined The 3D DIC technique is proven to be an effective method to conduct dynamic full-field deformation measurement.

scholarly journals The Use of 2D and 3D High-Speed Digital Image Correlation in Full Field Strain Measurements of Composite Materials Subjected to High Strain Rates

Proceedings ◽  
2018 ◽  
Vol 2 (8) ◽  
pp. 538 ◽  
Author(s):  
Ahmed Elmahdy ◽  
Patricia Verleysen
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
High Speed ◽  
High Strain ◽  
Image Correlation ◽  
Full Field ◽  
3D Digital Image Correlation ◽  
Gauge Section ◽  
2D And 3D ◽  
Dic Technique

The aim of this paper is to assess and compare the performance of both high speed 2D and 3D digital image correlation (DIC) configurations in the characterization of unidirectional carbon fiber reinforced epoxy composites in high strain rate tension in the transverse direction. The criteria for assessment were in terms of strain resolution and measuring the strain localization within the gauge section. Results showed the high-speed 3D DIC technique has lower strain resolution compared to the high-speed 2D DIC technique. In addition, the analysis of the full strain fields indicated that the 3D DIC technique could accurately locate and measure the concentrations of strains within the gauge section of the tested samples.

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.

Full Field Measurements of the Dynamic Response of AA6061-T6 Aluminum Alloy Under High Strain Rate Compression and Torsion Loads

2012 ◽  
Author(s):  
Gbadebo Owolabi ◽  
Daniel Odoh ◽  
Akindele Odeshi ◽  
Horace Whitworth
Keyword(s):  
Aluminum Alloy ◽  
High Speed ◽  
High Strain ◽  
Shear Bands ◽  
Field Measurements ◽  
Image Correlation ◽  
Deformation Analysis ◽  
Deformation And Failure ◽  
Full Field ◽  
Structural Applications

Aluminum alloys exhibit an attractive combination of mechanical and physical properties such as high stiffness and low density, which favors their utilization in many structural applications. Thus, increasing the structural applications of aluminum alloy is the driving force for the need to adequately understand its deformation and failure mechanisms under various types of dynamic loading conditions. In this study, full field plastic deformation of AA6061-T6 aluminum alloy at high strain-rates under compressive and torsion loads are measured using split Hopkinson compression and torsion bars and a high speed digital image correlation system. The stress-strain curves obtained using the high speed digital cameras are compared with results obtained from the elastic waves in the compression and torsion bars. A post deformation analysis of the specimen also shows strain localization along narrow adiabatic shear bands in the AA6061-T6 alloy.

Static and Dynamic Deformation Measurements of Micro Beams by the Technique of Digital Image Correlation

2006 ◽  
Vol 326-328 ◽  
pp. 211-214 ◽  
Author(s):  
Xiao Yuan He ◽  
Wei Sun ◽  
Xiang Zheng ◽  
Meng Nie
Keyword(s):  
Dynamic Characteristics ◽  
High Speed ◽  
Dynamic Deformation ◽  
Full Range ◽  
Frame Rate ◽  
Image Correlation ◽  
Static Tests ◽  
Full Field ◽  
Fringe Patterns ◽  
Vibration Parameters

It is critical to measure the static and dynamic deformation of the micro beam over their full range of voltage and frequency inputs, which are key parameters for predicting device behavior. In this study, full-field technique by correlation of projected fringe patterns is selected to determine static deformation, while dynamic parameters can be obtained by DIC with high-speed CMOS camera, whose maximal frame rate is 32k f/s. The static tests of micro beams are carried out by applying electric field forces under different dc voltage, while the dynamic tests are excited by harmonic excitations. Using the DIC method, the whole field in-plane or out-of-plane displacements of the micro beams are obtained, and hence the dynamic characteristics by post-processing of vibration analysis. Experimental results including the bending deformation and vibration parameters are reported and compared with finite element method. This study verifies the feasibility of this technique to measure both static and dynamic characteristics of MEMS components.

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.

Thermal Shock Effects on Dynamic Deformation Mechanisms in Ti2AlC

2012 ◽  
Author(s):  
R. Bhattacharya ◽  
N. C. Goulbourne
Keyword(s):  
Thermal Shock ◽  
High Speed ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Deformation ◽  
Compressive Loading ◽  
Image Correlation ◽  
Deformation Mechanisms ◽  
Hopkinson Pressure Bar ◽  
High Speed Imaging ◽  
Full Field

The present study is aimed at understanding the effects of thermal shock and associated microstructural features on the dynamic deformation mechanisms in Ti2AlC, a Mn+1AXn phase ternary ceramic. These materials crystallize in a Hexagonal Close Packed (HCP) structure with a c/a ratio greater than 1.67 which results in kink band formations when subjected to loading. In this work, we report the microstructural changes associated with thermal shocking of Mn+1AXn phases and its effects on deformation mechanisms, under dynamic compressive loading. The specimens are heated to temperatures of 220, 550 and 900°C, held at each temperature for 5–10 minutes, and subsequently quenched in water at 20°C to induce thermal shock. The thermal shock resistance and its effect on mechanical properties is investigated by subjecting heat treated specimens to compressive loading at high strain rates (∼1000–4500 s−1) using a Split Hopkinson Pressure Bar (SHPB). The microstructures of thermally shocked specimens are characterized by Scanning Electron Microscopy (SEM) combined with Energy Dispersive Spectroscopy (EDS) analysis to reveal the surface morphologies and characteristics. The displacements during the deformation events are captured using in situ high speed imaging, with full-field 2D Digital Image Correlation (DIC) technique. The key microscale mechanisms of deformation are studied using SEM analysis of deformed/fractured specimens.

Full-field modal analysis during base motion excitation using high-speed 3D digital image correlation

2017 ◽  
Vol 28 (10) ◽  
pp. 105402 ◽  
Author(s):  
Ángel J Molina-Viedma ◽  
Elías López-Alba ◽  
Luis Felipe-Sesé ◽  
Francisco A Díaz
Keyword(s):  
Digital Image Correlation ◽  
Modal Analysis ◽  
Digital Image ◽  
High Speed ◽  
Image Correlation ◽  
Full Field ◽  
3D Digital Image Correlation

scholarly journals Full-Field Operational Modal Analysis of an Aircraft Composite Panel from the Dynamic Response in Multi-Impact Test

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1602
Author(s):  
Ángel Molina-Viedma ◽  
Elías López-Alba ◽  
Luis Felipe-Sesé ◽  
Francisco Díaz
Keyword(s):  
Modal Analysis ◽  
Energy Absorption ◽  
High Speed ◽  
Operational Modal Analysis ◽  
Modal Identification ◽  
Image Correlation ◽  
Composite Panel ◽  
Impact Excitation ◽  
Full Field ◽  
The Impact

Experimental characterization and validation of skin components in aircraft entails multiple evaluations (structural, aerodynamic, acoustic, etc.) and expensive campaigns. They require different rigs and equipment to perform the necessary tests. Two of the main dynamic characterizations include the energy absorption under impact forcing and the identification of modal parameters through the vibration response under any broadband excitation, which also includes impacts. This work exploits the response of a stiffened aircraft composite panel submitted to a multi-impact excitation, which is intended for impact and energy absorption analysis. Based on the high stiffness of composite materials, the study worked under the assumption that the global response to the multi-impact excitation is linear with small strains, neglecting the nonlinear behavior produced by local damage generation. Then, modal identification could be performed. The vibration after the impact was measured by high-speed 3D digital image correlation and employed for full-field operational modal analysis. Multiple modes were characterized in a wide spectrum, exploiting the advantages of the full-field noninvasive techniques. These results described a consistent modal behavior of the panel along with good indicators of mode separation given by the auto modal assurance criterion (Auto-MAC). Hence, it illustrates the possibility of performing these dynamic characterizations in a single test, offering additional information while reducing time and investment during the validation of these structures.

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