The effects of the moisture content of laminated veneer lumber on bending strength and deformation determination via two-dimensional digital image correlation

2021 ◽  
pp. 095440622098618
Author(s):  
Eser Sözen ◽  
Kadir Kayahan ◽  
Timuçin Bardak ◽  
Selahattin Bardak
Keyword(s):  
Digital Image Correlation ◽  
Moisture Content ◽  
Digital Image ◽  
Bending Strength ◽  
Image Correlation ◽  
Bending Test ◽  
Homogeneous Distribution ◽  
Two Dimensional ◽  
Laminated Veneer Lumber ◽  
Strength And Deformation

This study determined the bending strength values of laminated veneer lumber (LVL) made with beech ( Fagus orientalis L.) veneer obtained by the peeling process and having four different moisture content values (0%/oven dry, 12%, 18%, and 25%). Bending tests were carried out in two different ways, i.e., for the flatwise and edgewise aspects of the LVL. Strain maps were created using two-dimensional digital image correlation (2 D DIC) and the samples having different moisture contents were compared. At the same time, the amount of displacement of the samples during the bending test was determined via conventional and DIC methods. Results of the study determined that the moisture content was effective in bending strength and tension zones. It was observed that increasing moisture content created homogeneous distribution of deformation. It was also observed that the data obtained by the 2 D DIC method were compatible with those obtained by the conventional method.

scholarly journals Simulation of the Hybrid Carbon-Aramid Composite Materials Based on Mechanical Characterization by Digital Image Correlation Method

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4184
Author(s):  
Camelia Cerbu ◽  
Stefania Ursache ◽  
Marius Florin Botis ◽  
Anton Hadăr
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Flexural Modulus ◽  
Image Correlation ◽  
Woven Fabric ◽  
Bending Test ◽  
Orthotropic Materials ◽  
The Impact ◽  
Longitudinal Strains ◽  
Hybrid Carbon

As hybrid carbon-aramid composites become widely used in various industries, it has become imperative to mechanically characterize them using accurate methods of measuring the entire deformation field such as the digital image correlation (DIC) method. The accuracy of the numerical simulation of carbon-aramid composite structures depends on the accuracy of the elastic constants. Therefore, the goal of this research is to model and simulate the mechanical behaviour of the composite based on epoxy resin reinforced with carbon-aramid woven fabric by considering the mechanical properties investigated by tensile test combined with DIC and the bending test. The curves of the transverse strains related to the longitudinal strains were investigated using DIC in order to determine the Poisson’s ratios in the case of tensile tests applied in warp or weft directions of the reinforcement fabric. The impact strength determined by Charpy tests is also reported. The other main objective is to use the analytical models to compute the tensile and flexural moduli of elasticity for the fictitious orthotropic materials which behave similarly to the carbon-aramid composite investigated. The simulations regarding the behaviour of the carbon-aramid composite in tensile and bending tests were validated by the experimental results, since the maximum errors recorded between experimental and theoretical results were 0.19% and 0.15% for the equivalent tensile modulus and for the equivalent flexural modulus, respectively.

scholarly journals A Review of Surface Deformation and Strain Measurement Using Two-Dimensional Digital Image Correlation

2016 ◽  
Vol 23 (3) ◽  
pp. 461-480 ◽  
Author(s):  
Sze-Wei Khoo ◽  
Saravanan Karuppanan ◽  
Ching-Seong Tan
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Strain Measurement ◽  
Surface Deformation ◽  
Optical Measurement ◽  
Image Correlation ◽  
Two Dimensional ◽  
Full Field ◽  
Computation Efficiency ◽  
Dimensional Measurements

Abstract Among the full-field optical measurement methods, the Digital Image Correlation (DIC) is one of the techniques which has been given particular attention. Technically, the DIC technique refers to a non-contact strain measurement method that mathematically compares the grey intensity changes of the images captured at two different states: before and after deformation. The measurement can be performed by numerically calculating the displacement of speckles which are deposited on the top of object’s surface. In this paper, the Two-Dimensional Digital Image Correlation (2D-DIC) is presented and its fundamental concepts are discussed. Next, the development of the 2D-DIC algorithms in the past 33 years is reviewed systematically. The improvement of 2DDIC algorithms is presented with respect to two distinct aspects: their computation efficiency and measurement accuracy. Furthermore, analysis of the 2D-DIC accuracy is included, followed by a review of the DIC applications for two-dimensional measurements.

Tension and compression moduli characterization of a bimodular ceramic-fiber reinforced SiO2 aerogel composite

2020 ◽  
Vol 62 (10) ◽  
pp. 1003-1009
Author(s):  
Yantao Sun ◽  
Jia Huang ◽  
Duoqi Shi ◽  
Shengliang Zhang ◽  
Zhizhong Fu ◽  
...  
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Image Correlation ◽  
Bending Test ◽  
Ceramic Fiber ◽  
Fiber Reinforced ◽  
Compression Tests ◽  
Tension Tests ◽  
Aerogel Composite ◽  
Tension And Compression

Abstract Comprehensive characterization mechanical properties of aerogels and their composites are important for engineering design. In particular, some aerogel composites were reported to have varied tension and compression moduli. But conducting tension tests is difficult for the reason that low strength and brittleness will lead to unexpected failure in the non-test area. A method is presented for measuring both the tension and compression moduli of a ceramic-fiber reinforced SiO2 aerogel composite by bending via digital image correlation. First, the relationship between bending behavior and the tension/compression moduli was introduced for bimodular materials. Then a bending test was conducted to predict tension and the compression moduli of the ceramicfiber- reinforced SiO2 aerogel composite via digital image correlation. In addition, uniaxial tension and compression tests of the aerogel composites were carried out, respectively for measuring tension and compression moduli. The tension and compression moduli measured were numerically similar to results obtained from uniaxial tests with a difference of less than 14 %.

Use of Digital Image Correlation for the Evaluation of Flexural Fatigue Behavior of Asphalt Beams with Geosynthetic Interlayers

2017 ◽  
Vol 2631 (1) ◽  
pp. 55-64 ◽  
Author(s):  
Vinay Kumar V ◽  
Sireesh Saride
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Digital Images ◽  
Fatigue Behavior ◽  
Bottom Layer ◽  
Fatigue Performance ◽  
Image Correlation ◽  
Bending Test ◽  
Flexural Fatigue ◽  
Tensile Strains

In this study, the flexural fatigue performance of two-layer asphalt beams with and without geosynthetic interlayers was evaluated with a digital image correlation (DIC) technique. A field scenario was simulated by considering an old, destressed pavement as the bottom layer with a compacted bituminous mix as an overlay. An appropriate tack coat and geosynthetic interlayer were at the interface. The digital images were recorded at a specific interval of load cycles during a repeated load four-point bending test. The displacement fields obtained from the digital images were analyzed so that the crack width, crack height, and tensile strains could be obtained and the crack initiation and propagation phenomena studied. The deformation data obtained from the DIC analysis were validated with the vertical deformations measured through linear variable differential transformers. The DIC results correlated very well with the measured data. The DIC data indicated that the tensile strains were as high as 4.75% at the crack tip in the control specimen compared with 1.42% in a polyester grid interlayered specimen at the failure of the corresponding specimens. With the inclusion of interlayers, the fatigue performance of the two-layer asphalt beam specimens improved by about 39, 12, and 1.7 times for Specimens I1, I2, and I3, respectively.

Self-correction method of out-of-plane motions in two-dimensional digital image correlation

2016 ◽  
Vol 232 (9) ◽  
pp. 1672-1676 ◽  
Author(s):  
Wentao Yan ◽  
Feng Lin
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Correlation Method ◽  
Correction Method ◽  
Image Correlation ◽  
Two Dimensional ◽  
Monitoring Method ◽  
Strain Monitoring ◽  
Out Of Plane ◽  
Relationship Of

Strain monitoring is very important in the manufacturing, assembling, installation and servicing processes in both mechanical and civil engineering fields. Two-dimensional digital image correlation is a simple, efficient strain monitoring method, but one major bottleneck is the unacceptable error due to the unavoidable out-of-plane motions of the object in practice. We propose a “self-correction” method: employing the originally extracted strain values in different directions to correct the errors due to out-of-plane motions. It is applicable to many engineering applications with known relationship of strains in different directions. A uniaxial tension test was conducted to demonstrate the effectiveness and practicality of this self-correction method. Compared with other correction methods, this method is not only simpler but also more efficient in correcting errors due to the lens distortion caused by self-heating. Both the experiment and theoretical analyses demonstrate that this self-correction method maintains the high accuracy of the digital image correlation method.

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