Determination of Young's modulus and shear modulus by means of deflection curves for wood beams obtained in static bending tests

Holzforschung ◽  
2007 ◽  
Vol 61 (5) ◽  
pp. 589-594 ◽  
Author(s):  
Koji Murata ◽  
Tsubasa Kanazawa
Keyword(s):  
Shear Modulus ◽  
Young’S Modulus ◽  
Polynomial Regression ◽  
Young's Modulus ◽  
Dynamic Properties ◽  
Flexural Vibration ◽  
Bending Test ◽  
Deflection Curve ◽  
Element Analysis ◽  
Static Young’S Modulus

Abstract Young's modulus and shear modulus were simultaneously obtained in a three-point bending test based on Timoshenko's bending theory. Deflection curves of a bent beam were measured by image analysis, and the mechanical properties of the wood were calculated by polynomial regression analysis after excluding the singular region. When beam specimens of spruce (Picea sp.) and mizunara (Quercus crispula) wood were tested, static Young's modulus (E s) and static shear modulus (G s) values could be obtained from the deflection curve using finite element analysis. By comparing the dynamic properties (E d and G d) obtained by a flexural vibration test, it was estimated that E s was greater than E d, while G s was less than G d. However, we suppose that the G s values calculated from the deflection curve are more plausible than those obtained from a conventional bending test.

Flatwise Young’s modulus and flatwise shear modulus of plywood measured by flexural vibration test

Holzforschung ◽  
2013 ◽  
Vol 67 (6) ◽  
pp. 683-690 ◽  
Author(s):  
Hiroshi Yoshihara
Keyword(s):  
Finite Element Analysis ◽  
Shear Modulus ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Flexural Vibration ◽  
Vibration Test ◽  
Specimen Length ◽  
Element Analysis ◽  
Flexural Vibration Test ◽  
Vibration Tests

Abstract The flatwise Young’s modulus and the flatwise shear modulus of 3-, 5-, and 7-ply plywoods made of Lauan (Shorea sp.) veneers have been determined by conducting flexural vibration tests with various specimen lengths and by finite element analysis. The results indicate that the flatwise Young’s modulus decreases with decreasing specimen length, whereas the opposite is true for the flatwise shear modulus.

Correlation Analysis between Dynamic Young’s Modulus and Static MOE of the Poplar LVL Reinforced with Multilayer Fiberglass Mesh

2010 ◽  
Vol 26-28 ◽  
pp. 936-939
Author(s):  
Li Zhang ◽  
Ying Cheng Hu
Keyword(s):  
Correlation Analysis ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Dynamic Properties ◽  
Longitudinal Vibration ◽  
Flexural Vibration ◽  
Transmission Method ◽  
Vibration Method ◽  
Dynamic Young’S Modulus ◽  
Dynamic Young's Modulus

In this paper, the poplar LVL was reinforced with multilayer fiberglass mesh. The reinforcing effect of adding position of fiberglass mesh on improving the static MOE was studied. And three different nondestructive testing (NDT) methods, such as the longitudinal transmission method, longitudinal vibration method and flexural vibration method (out-plane and in-plane), were used to test the dynamic properties of the reinforced poplar LVL. The correlation analysis was implemented between the dynamic Young’s modulus and the static MOE of the reinforced poplar LVL. It can be concluded that the three NDT methods are useful for predicting the MOE of reinforced LVL, but the flexural and longitudinal vibration methods had better accuracy to estimate the MOE.

Off-axis Young’s modulus and off-axis shear modulus of wood measured by flexural vibration tests

Holzforschung ◽  
2012 ◽  
Vol 66 (2) ◽  
Author(s):  
Hiroshi Yoshihara
Keyword(s):  
Shear Modulus ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Flexural Vibration ◽  
Transformation Rule ◽  
Rule Based ◽  
Free Condition ◽  
Flexural Vibration Test ◽  
Vibration Tests ◽  
The Relationship

Abstract The off-axis Young’s modulus and off-axis shear modulus of wood were obtained by conducting a flexural vibration test under the free-free condition, and performing a subsequent numerical analysis on the test data. The relationship between the off-axis Young’s modulus and the off-axis angle was obtained. In contrast, the relationship between the off-axis shear modulus and the off-axis angle was discrepant from that predicted by the transformation rule based on the conventional hypothesis that Timoshenko’s shear factor is 1.2. When the dependence of the shear factor on the off-axis angle was taken into account, however, the off-axis shear modulus could be obtained properly.

Dynamic Properties of Wood-Plastic Composites

2011 ◽  
Vol 101-102 ◽  
pp. 1078-1081
Author(s):  
Gui Wen Yu ◽  
Shuang Lan ◽  
Jian Yuan Feng ◽  
Zhuang Liu
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Dynamic Properties ◽  
Bending Test ◽  
Wood Plastic Composites ◽  
Three Point Bending ◽  
Dynamic Young’S Modulus ◽  
Bending Modulus ◽  
Plastic Composites ◽  
Dynamic Young's Modulus

Wood-plastic composites (WPC) , which were made of virgin high-density polyethylene (HDPE) with poplar fibers as filler, were measured by three vibration nondestructive testing (NDT) methods. The values of dynamic Young’s modulus of specimens were measured by different vibration NDT methods, and the values of static bending modulus of elasticity (MOE) were also determined by three point bending test according to ASTM D790-03. The paper analyzed the variability of the dynamic young’s modulus of WPC based on virgin HDPE obtained with different NDT methods, and the correlativity was also estimated between the dynamic Young’s modulus and the static MOE of WPC based on virgin HDPE. These results suggest that WPC can be made of virgin HDPE, and the NDT methods are appropriate to estimate the dynamic Young’s modulus of WPC based on virgin HDPE.

Analysis on Microstructure and Mechanical Properties of Pine Laminated Veneer Lumber

2010 ◽  
Vol 658 ◽  
pp. 479-482
Author(s):  
Bing Xue ◽  
Ying Cheng Hu ◽  
Fang Chao Cheng ◽  
Li Zhang
Keyword(s):  
Young’S Modulus ◽  
Compression Ratio ◽  
Bending Strength ◽  
Young's Modulus ◽  
Longitudinal Vibration ◽  
Flexural Vibration ◽  
Bending Test ◽  
Transmission Method ◽  
Vibration Method ◽  
Laminated Veneer Lumber

In this paper, four different nondestructive testing (NDT) methods and the static bending test were conducted on the pine (Pinus sylvestris L. Var. mongolica Litven.) laminated veneer lumber (LVL). The NDT methods included the longitudinal transmission method, longitudinal vibration method, in-plane and out-plane flexural vibration method. The effects of the compression ratio on the Young’s modulus and bending strength (MOR) of LVL were investigated. There were four compression ratios for different ply numbers of LVL, 8.1% for eight-ply samples, 18.3% for nine-ply samples, 26.5% for ten-ply samples, 33.1% for eleven-ply samples, respectively. The microscopic structure of the LVL was analyzed with a scanning electron microscope (SEM). The results showed that the microstructure of LVL changed greatly between different compression ratios. And the dynamic Young’s modulus and static bending (MOE) and bending strength (MOR) were greatly increased when the compression ratio increased form 18.3% to 26.5%.

Young’s modulus and shear modulus of solid wood measured by the flexural vibration test of specimens with large height/length ratios

Holzforschung ◽  
2015 ◽  
Vol 69 (4) ◽  
pp. 493-499 ◽  
Author(s):  
Hiroshi Yoshihara ◽  
Masahiro Yoshinobu
Keyword(s):  
Shear Modulus ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Flexural Vibration ◽  
Solid Wood ◽  
Accurate Calculation ◽  
Rigorous Solution ◽  
Vibration Equation ◽  
Free Condition ◽  
Flexural Vibration Test

Abstract The Young’s modulus (modulus of elasticity, MOE) in the longitudinal (L) and radial (R) directions and the shear modulus (SM) in the LR plane of Douglas fir were determined by the flexural vibration (FV) tests under the free-free condition based on Timoshenko’s vibration equation. In the tests, the height/length (H/L) ratio was varied from 0.05 to 0.3. In addition, the test data were analyzed numerically and the effectiveness of Timoshenko’s equation was examined. The MOE and SM were calculated based on the rigorous and approximated solutions of Timoshenko’s equation. The inaccuracy of the approximated solution was enhanced when the H/L ratio of the specimen was too large. In contrast, the rigorous solution enabled the accurate calculation of these moduli in a wider range of length/depth ratios than the approximated solution.

Measurement of the Young’s modulus and shear modulus of extruded polystyrene foam by the longitudinal and flexural vibration methods

2016 ◽  
Vol 54 (2) ◽  
pp. 199-216 ◽  
Author(s):  
Hiroshi Yoshihara ◽  
Naoki Ataka ◽  
Makoto Maruta
Keyword(s):  
Cell Wall ◽  
Shear Modulus ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Flexural Vibration ◽  
Vibration Test ◽  
Polystyrene Foam ◽  
Shear Tests ◽  
Vibration Tests ◽  
Extruded Polystyrene Foam

The Young’s modulus and shear modulus of extruded polystyrene foam were obtained by measurements using the longitudinal and flexural vibration methods on specimens with various lengths and performing a subsequent numerical analysis on the test data. In addition to the vibration tests, ISO 844 compression and ASTM C273/C273M-11 shear tests were conducted, and the results were compared with those obtained from the vibration tests. The Young’s modulus values could be measured accurately by the longitudinal and flexural vibration tests while reducing the effects of the specimen configuration. In contrast, the shear modulus value was often dependent on the specimen configuration. The Young’s modulus and shear modulus values obtained from the vibration tests were often higher than those obtained from the standardised tests because the bending of cell wall is not induced in the vibration test. Although a provisional method for reducing the influence of the specimen configuration was proposed based on the numerical results, further research is required to measure the elastic modulus of extruded polystyrene foam accurately.

A study of the anisotropic static and dynamic elastic properties of transversely isotropic rocks

Geophysics ◽  
2019 ◽  
Vol 84 (6) ◽  
pp. C281-C293 ◽  
Author(s):  
Fei Gong ◽  
Bangrang Di ◽  
Jianxin Wei ◽  
Pinbo Ding ◽  
He Tian ◽  
...  
Keyword(s):  
Young’S Modulus ◽  
Clay Minerals ◽  
Elastic Properties ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Dynamic Properties ◽  
Axial Stress ◽  
Poisson's Ratio ◽  
Static Young’S Modulus ◽  
Loading And Unloading

The elastic properties of rock are major factors affecting hydraulic fracturing. Static elastic properties can be estimated using geomechanical laboratory tests, whereas dynamic properties can be estimated from elastic-wave velocity and rock density. We prepared two synthetic shales containing different clay minerals and one natural shale and focused on the elastic properties for the full tensor of elasticity and their anisotropy. The static and dynamic properties of these dry samples were obtained based on triaxial tests during loading and unloading. The results suggest that the synthetic and natural shale indicate high similarity in the static and dynamic properties. The dynamic Young’s modulus and Poisson’s ratio increase with increasing axial stress during loading and unloading. For the static properties, the static Poisson’s ratio increases with axial stress during loading and unloading. However, differences exist between the static and dynamic Young’s moduli during loading, with the static Young’s modulus decreases with the increasing axial stress at a high stress level. In addition, the static Young’s modulus is consistently lower than the dynamic Young’s modulus during loading and unloading, but the static Poisson’s ratio is larger or smaller than the dynamic Poisson’s ratio. During loading and unloading, there could be approximately a 30% difference when estimating static elastic properties from the static-dynamic relations, depending on which static moduli are used. Furthermore, the static and dynamic properties of the samples are strongly anisotropic, and the anisotropy of elastic properties is sensitive to the axial stress and the clay minerals.

Mechanical Properties and Decay Resistance of Wood Polymer Composites (WPC)

2011 ◽  
Vol 264-265 ◽  
pp. 819-824 ◽  
Author(s):  
Md. Rezaur Rahman ◽  
Sinin Hamdan ◽  
M. Saiful Islam ◽  
Md. Shahjahan Mondol
Keyword(s):  
Polymer Composites ◽  
Young’S Modulus ◽  
Modulus Of Elasticity ◽  
Young's Modulus ◽  
Decay Resistance ◽  
Modulus Of Rupture ◽  
Wood Polymer ◽  
Static Young’S Modulus ◽  
Wood Polymer Composites ◽  
Wood Polymer Composite

In Malaysia, especially Borneo Island Sarawak has a large scale of tropical wood species. In this study, selected raw tropical wood species namely Artocarpus Elasticus, Artocarpus Rigidus, Xylopia Spp, Koompassia Malaccensis and Eugenia Spp were chemically treated with sodium meta periodate to convert them into wood polymer composites. Manufactured wood polymer composites were characterized using mechanical testing (modulus of elasticity (MOE), modulus of rupture (MOR), static Young’s modulus) and decay resistance test. Modulus of elasticity and modulus of rupture were calculated using three point bending test. Static Young’s modulus and decay resistance were calculated using compression parallel to gain test and natural laboratory decay test respectively. The manufactured wood polymer composites yielded higher modulus of elasticity, modulus of rupture and static Young’s modulus. Wood polymer composite had high resistant to decay exposure, while Eugenia Spp wood polymer composite had highly resistant compared to the other ones.

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