Damage Evolution of Composite Laminates with Digital Image Correlation

2010 ◽  
Vol 452-453 ◽  
pp. 377-380 ◽  
Author(s):  
Simone Giancane ◽  
Riccardo Nobile ◽  
Francesco W. Panella ◽  
Vito Dattoma
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Composite Laminates ◽  
Damage Evolution ◽  
Tensile Load ◽  
Reference Points ◽  
Image Correlation ◽  
Full Field ◽  
Two Parameters ◽  
Dic Technique

DIC (Digital Image Correlation) based methodology gives full field measure of the displacement using a well defined algorithm for matching the images of loaded and load free component, so that displacement in a plane can be evaluated for a certain number of grid reference points on the analysed surface. In this work, the authors present an application of DIC technique to analyse fatigue damage phenomena in two notched GFRC laminates under tensile load. Damage analysis based on optical DIC technique has been performed to detect the damaged areas on the specimen surface. The damage evolution and failure mechanism has been followed monitoring two parameters: the local hysteresis area of stress-strain cycles, the local stiffness variation.

Development of a Railway Track Displacement Monitoring by Using Digital Image Correlation Technique

2014 ◽  
Vol 548-549 ◽  
pp. 683-687 ◽  
Author(s):  
Lenny Iryani ◽  
Hery Setiawan ◽  
Tatacipta Dirgantara ◽  
Ichsan Setya Putra
Keyword(s):  
Digital Image Correlation ◽  
Stress Field ◽  
Digital Image ◽  
Displacement Field ◽  
Image Correlation ◽  
Railway Track ◽  
Remaining Life ◽  
Full Field ◽  
Field Displacement ◽  
Dic Technique

To avoid an unnecessary catastrophic accident due to a failure of a railway track, it is important to have a reliable condition monitoring system for the railway track. The integrity of the railway track can be assessed by monitoring the displacement field of the track, which can then be used to determine the strain and stress field. By knowing the stress history of the track and the S–N curves of the track material, the remaining life of the railway track can be predicted. In the present work, a simple system to monitor and record the displacement field of the railway track has been developed by using Digital Image Correlation (DIC) technique. The set–up to monitor the displacement field of the railway track was developed using a high speed video camera of Nikon J1 to capture the image of the railway track when the train passing through. The DIC technique was then employed off line to measure the displacement field of the 2D image captured. The results showed that the full field displacement measured by using DIC technique gives a good agreement compared to the finite element results. The full field displacement can be used to calculate the strain-stress field, and later on the remaining life assessment can be conducted based on the results.

Characterization of LIGA Microsystems Using Digital Image Correlation Technique and SEM Imaging

Aerospace ◽  
2005 ◽  
Author(s):  
Helena (Huiqing) Jin ◽  
Wei-Yang Lu ◽  
Jeff Chames ◽  
Nancy Yang
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Speckle Pattern ◽  
Image Correlation ◽  
Specimen Surface ◽  
Correlation Technique ◽  
Sem Images ◽  
Full Field ◽  
Speckle Patterns ◽  
Dic Technique

A new experimental technique was developed to characterize the mechanical properties of LIGA (an acronym from German words for lithography, electroplating, and molding) materials. An advanced imaging capability, scanning electron microscopy (SEM), with an integrated loading stage allows the acquisition of in situ microstructural images at the micro scale during loading. The load is measured directly from a load cell, and the displacement field is calculated from the SEM images based on the digital image correlation (DIC) technique. The DIC technique is a full-field deformation measurement technique which obtains displacement fields by comparing random speckle patterns on the specimen surface before and after deformation. The random speckle patterns are typically generated by applying a thin layer of material with high contrast to a specimen surface. Alternatively, DIC can also be applied using the microstructural features of a surface as texture patterns for correlation. DIC technique is ideally suited to characterize the deformation field of MEMS structures without the need to generate a random speckle pattern, which can be very challenging on the micro and nanoscale. In this paper, the technique is experimentally demonstrated on a LIGA specimen. The digital images showing LIGA surface features acquired during the loading can serve as random patterns for the DIC method. Therefore, full-field displacement and strain can be obtained directly on the specimen and the errors incurred by the testing system can be eliminated.

Characterization of Mechanical Behavior of Polyurethane Foams Using Digital Image Correlation

2005 ◽  
Author(s):  
Helena (Huiqing) Jin ◽  
Wei-Yang Lu ◽  
Simon Scheffel ◽  
Michael K. Neilsen ◽  
Terry D. Hinnerichs
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Polyurethane Foams ◽  
Image Correlation ◽  
Compression Tests ◽  
Steel Cylinder ◽  
Full Field ◽  
Strain Concentration ◽  
The Impact ◽  
Dic Technique

Polyurethane foams have good energy absorption properties and are effective in protecting sensitive components from damages due to impact. The foam absorbs impact energy by crushing cells and undergoing large deformation. The complex deformation of the foam needs to be modeled accurately to simulate the impact events. In this paper, the Digital Image Correlation (DIC) technique was implemented to obtain the deformation field of foam specimens under compression tests. Images of foam specimen were continuously acquired using high-speed cameras. The full field displacement and strain at each incremental step of loading were calculated from these images. The closed-cell polyurethane foam used in this investigation was nominal 0.32 kg/m^3 (20 pcf). In the first experiment, cubic specimens were compressed uniaxially up to 60%. The full-field displacements and strains obtained using the DIC technique provide detailed information about the inhomogeneous deformation over the area of interest during loading. In the second experiment, compression tests were conducted for a simple foam structure - cubic foam specimens with a steel cylinder inclusion. The strain concentration at the interface between steel cylinder and foam was studied to simulate the deformation of foam in a typical application. In the third experiment, the foam was loaded from the steel cylinder during the compression. The strain concentration at the interface and the displacement distribution over the surface were compared for cases with and without a confinement fixture to study the effects of confinement. These experimental results demonstrate that the DIC technique can be applied to polyurethane foams to study the heterogeneous deformation. The experimental data is briefly compared with the results from modeling and simulation using a viscoplastic model for the foam.

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.

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.

Investigation of the effect of damage on the strength of notched composite laminates by digital image correlation

2005 ◽  
Vol 40 (5) ◽  
pp. 451-461 ◽  
Author(s):  
R Ambu ◽  
F Aymerich ◽  
F Bertolino
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Residual Strength ◽  
Composite Laminates ◽  
Correlation Method ◽  
Strength Properties ◽  
Image Correlation ◽  
Correlation Technique ◽  
Digital Image Correlation Method ◽  
Full Field

In this paper the results of an experimental investigation on the effect of subcritical damage on the residual strength properties of notched composite laminates are presented. A procedure based on the digital image correlation method was applied to laminates subjected to static and fatigue tensile loading. The digital image correlation method (DICM) is a whole-field technique that calculates surface displacements and strains from digital images characterized by a random distribution of intensity grey levels. Graphite/PEEK (polyether ether ketone) and graphite/epoxy laminates with different stacking sequences were analysed and the damage progression near the stress riser was evaluated by means of the strain maps obtained by digital image correlation. It was found that damage developing before final fracture may significantly affect the structural performance of composite laminates. The digital image correlation technique allowed clarification of the beneficial or detrimental role played by the different failure mechanisms on the strain redistribution around the hole and, as a consequence, on the residual strength and fatigue life of notched samples. The findings of the investigation suggest that the DICM is an efficient and reliable tool for full-field monitoring and detailed damage characterization of structural composite elements.

scholarly journals Experimental Characterization of the FRCM-Concrete Interface Bond Behavior Assisted by Digital Image Correlation

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1154
Author(s):  
Dario De Domenico ◽  
Antonino Quattrocchi ◽  
Damiano Alizzio ◽  
Roberto Montanini ◽  
Santi Urso ◽  
...  
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Mechanical Tests ◽  
Image Correlation ◽  
Front Face ◽  
Full Field ◽  
Bond Behavior ◽  
Externally Bonded ◽  
Strengthening Technique ◽  
Concrete Interface

Digital Image Correlation (DIC) provides measurements without disturbing the specimen, which is a major advantage over contact methods. Additionally, DIC techniques provide full-field maps of response quantities like strains and displacements, unlike traditional methods that are limited to a local investigation. In this work, an experimental application of DIC is presented to investigate a problem of relevant interest in the civil engineering field, namely the interface behavior between externally bonded fabric reinforced cementitious mortar (FRCM) sheets and concrete substrate. This represents a widespread strengthening technique of existing reinforced concrete structures, but its effectiveness is strongly related to the bond behavior between composite fabric and underlying concrete. To investigate this phenomenon, a set of notched concrete beams are realized, reinforced with FRCM sheets on the bottom face, subsequently cured in different environmental conditions (humidity and temperature) and finally tested up to failure under three-point bending. Mechanical tests are carried out vis-à-vis DIC measurements using two distinct cameras simultaneously, one focused on the concrete front face and another focused on the FRCM-concrete interface. This experimental setup makes it possible to interpret the mechanical behavior and failure mode of the specimens not only from a traditional macroscopic viewpoint but also under a local perspective concerning the evolution of the strain distribution at the FRCM-concrete interface obtained by DIC in the pre- and postcracking phase.

scholarly journals Strain Monitoring on Damaged Composite Laminates Using Digital Image Correlation

2015 ◽  
Vol 99 ◽  
pp. 353-360 ◽  
Author(s):  
Bataxi ◽  
Xi Chen ◽  
Zhefeng Yu ◽  
Hai Wang ◽  
Cees Bil
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Composite Laminates ◽  
Image Correlation ◽  
Strain Monitoring
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