Large Deformation Strain Measurement Using Digital Image Correlation Technique During Axial Crushing of an Extruded AA-6063 Tube

2016 ◽  
Author(s):  
Arun Kumar Sudalaiyandi ◽  
Ramesh Krishnamurthi ◽  
Raghu V. Prakash
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Tensile Deformation ◽  
Compressive Load ◽  
Image Correlation ◽  
Correlation Technique ◽  
Thin Wall ◽  
Full Field ◽  
Static Test ◽  
Thin Walled

Thin-walled metal tubes are extensively used in aircraft and automobile industries as energy absorbers during collision. When a thin wall tube is subjected to an axial compressive load, lobes are formed sequentially and each lobe undergoes a large plastic deformation without any cracking; this is referred to as progressive buckling. The focus of this paper is to study the displacement and strain fields near the buckled zone of a thin-walled square tube both experimentally and numerically. Quasi-static test was conducted on thin-walled square tubes made of aluminum alloy AA-6063 and the displacement and full-field strain was measured using Digital Image Correlation (DIC) technique. It is noted that while one face of the tube undergoes tensile deformation, the adjacent faces undergo compressive deformation. The strain levels exceed the fracture strain obtained during a tensile test. Strain estimated from DIC was found to be in good agreement with the strain gauge measurements at far field. Further, strain estimations obtained through numerical simulations showed a reasonable agreement with DIC measurements.

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.

Buckling Measurement of Cylindrical Shells by Digital Image Correlation Method

2013 ◽  
Author(s):  
Tzu-Yu Kuo ◽  
Wei-Chung Wang ◽  
Chun-I Chu ◽  
Jia-He Chen ◽  
Te-Heng Hung ◽  
...  
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Strain Measurement ◽  
Cylindrical Shells ◽  
Compressive Load ◽  
Correlation Method ◽  
Tensile Tests ◽  
Image Correlation ◽  
Strain Gages ◽  
Full Field

In this study, deformation of cylindrical shells under axial compressive load was studied and characterized by a noncontact detection technique, called digital image correlation (DIC). As opposed to commonly used strain gages for measuring structure strains at specific points, the DIC method can render not only 2D but also 3D full-field measurements for strain as well as structure deformation. The accuracy of strain measurement obtained using the DIC method was carefully validated by following ASTM standard E8 for strain measurement using strain gages in tensile tests. The DIC technique provided convenient measurements for characterizing the buckling behaviors of defective cylindrical shell samples. This study has engineering implications for providing 3D strain and deformation analyses to ensure structure reliability and safety.

Error Estimations in Digital Image Correlation Technique

2007 ◽  
Vol 7-8 ◽  
pp. 265-270 ◽  
Author(s):  
Thorsten Siebert ◽  
Thomas Becker ◽  
Karsten Spiltthof ◽  
Isabell Neumann ◽  
Rene Krupka
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Optical Measurement ◽  
Measurement Techniques ◽  
Image Correlation ◽  
Field Analysis ◽  
Correlation Technique ◽  
Full Field ◽  
Wide Range ◽  
The Impact

The reliability for each measurement technique depends on the knowledge of it’s uncertainty and the sources of errors of the results. Among the different techniques for optical measurement techniques for full field analysis of displacements and strains, digital image correlation (DIC) has been proven to be very flexible, robust and easy to use, covering a wide range of different applications. Nevertheless the measurement results are influenced by statistical and systematical errors. We discuss a 3D digital image correlation system which provides online error information and the propagation of errors through the calculation chain to the resulting contours, displacement and strains. Performance tests for studying the impact of calibration errors on the resulting data are shown for static and dynamic applications.

scholarly journals Experimental Investigation on the Mechanical Behavior of Bovine Bone Using Digital Image Correlation Technique

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Yuxi Chen ◽  
Diansen Yang ◽  
Yongshang Ma ◽  
XianJun Tan ◽  
Zhan Shi ◽  
...  
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Image Correlation ◽  
Bending Test ◽  
Displacement Sensor ◽  
Fracture Mechanisms ◽  
Correlation Technique ◽  
Bovine Bone ◽  
Full Field ◽  
Force Direction

In order to understand the fracture mechanisms of bone subjected to external force well, an experimental study has been performed on the bovine bone by carrying out the three-point bending test with 3D digital image correlation (DIC) method, which provides a noncontact and full field of displacement measurement. The local strain and damage evolution of the bone has been recorded real time. The results show that the deflection measured by DIC agrees well with that obtained by the displacement sensor of the mechanical testing machine. The relationship between the deflection and the force is nearly linear prior to reaching the peak strength which is about 16 kN for the tested bovine tibia. The full-field strain contours of the bone show that the strain distribution depends on not only the force direction, but also the natural bone shape. The natural arched-shape bovine tibia bone could bear a large force, due to the tissue structure with high strength, and the fracture propagation process of the sample initiates at the inner side of the bone first and propagates along the force direction.

Full-Field Modal Analysis by Using Digital Image Correlation Technique

2021 ◽  
pp. 105-112
Author(s):  
Davide Mastrodicasa ◽  
Emilio Di Lorenzo ◽  
Simone Manzato ◽  
Bart Peeters ◽  
Patrick Guillaume
Keyword(s):  
Digital Image Correlation ◽  
Modal Analysis ◽  
Digital Image ◽  
Image Correlation ◽  
Correlation Technique ◽  
Digital Image Correlation Technique ◽  
Full Field

Dynamic Material Characterization Using Digital Image Correlation

2014 ◽  
Vol 566 ◽  
pp. 3-9
Author(s):  
Amos Gilat ◽  
Jeremy D. Seidt
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
High Speed ◽  
Image Correlation ◽  
Correlation Technique ◽  
Full Field ◽  
Punch Test ◽  
Dynamic Experiments ◽  
Split Hopkinson ◽  
Rate Test

Digital Image Correlation is a non-contact optical technique for measuring the full-field deformation on the surface of a deforming specimen. The technique was initially used in quasi-static experiments, but with the development of high speed digital cameras is used also in dynamic experiments. This use of the Digital Image Correlation technique in several dynamic experiments is presented. This includes the compression and tensile split Hopkinson bar tests, a shear test for specimens made of sheet metal, a dynamic punch test, tensile test of Kevlar cloth and Kevlar yarn, and an intermediate strain rate test in compression.

scholarly journals Digital Image Correlation Comparison of Damaged and Undamaged Aeronautical CFRPs During Compression Tests

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 249 ◽  
Author(s):  
Claudia Barile ◽  
Caterina Casavola ◽  
Giovanni Pappalettera
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Compressive Load ◽  
Strain Analysis ◽  
Region Of Interest ◽  
Field Measurements ◽  
Image Correlation ◽  
Compression Tests ◽  
Full Field ◽  
Aerospace Applications

The diffusion of composite materials in aeronautical and aerospace applications is attributable to the high specific mechanical properties they offer. In particular, the recent use of Carbon Fiber Reinforced Polymer (CFRP) materials is highly increased. The main disadvantage in using this kind of material is related to the possibility of including damages or defects not visible on the surface that compromise their behavior and make their use extremely unsafe if not properly supervised. The most conventional nondestructive techniques allow the detection of damages when they already compromise the life of these materials. The use of the same techniques makes it harder to monitor in-situ of the progress of damages, especially if they occur inside the materials. The implementation of the innovative strain analysis method, like those based on full-field measurements, could provide additional information about the damage mechanisms by supplying the complete strain distribution of the surface of the sample. The present paper examines the mechanical behavior of two different CFRP specimens, with and without damage, subjected to compressive load in an anti-buckling fixture by using the Digital Image Correlation (DIC). The purpose is to measure the out-of-plane displacements, characteristics of the compression tests, in all the points of the ROI (Region of Interest), using a full-field and noncontact technique. The innovative aspect of this work is therefore to solve this problem through an experimental approach with DIC 3D technique.

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.

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