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.

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.

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.

Comparison of results obtained by static 3- and 4-point bending and flexural vibration tests on solid wood, MDF, and 5-plywood

Holzforschung ◽  
2013 ◽  
Vol 67 (8) ◽  
pp. 941-948 ◽  
Author(s):  
Hiroshi Yoshihara
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Medium Density Fiberboard ◽  
Flexural Vibration ◽  
Solid Wood ◽  
Bending Tests ◽  
Four Point Bending ◽  
Flexural Vibration Test ◽  
The Difference ◽  
Vibration Tests

Abstract The flexural Young’s modulus of western hemlock, medium-density fiberboard, and 5-plywood (made of lauan) has been determined by conducting three- and four-point bending tests with various span lengths and by flexural vibration test. The Young’s modulus was significantly influenced by the deflection measurement method. In particular, the Young’s modulus was not reliable based on the difference between the deflections at two specific points in the specimen, although this test is standardized according to ISO 3349-1975 and JIS Z2101-2009.

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.

Correlations among Physical and Mechanical Parameters of Rocks

2017 ◽  
Vol 865 ◽  
pp. 366-372
Author(s):  
Jing Sen Liu ◽  
Hai Bo Li ◽  
Guo Kai Zhang ◽  
Jian Deng
Keyword(s):  
Shear Modulus ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
P Wave ◽  
Physical Parameters ◽  
Dynamic Shear Modulus ◽  
Regression Equations ◽  
Mechanical Parameters ◽  
P Wave Velocity ◽  
The Relationship

In order to improve the accuracy of the rock mechanical parameters, the correlations among physical and mechanical parameters were investigated. A large number of laboratory testing results curried out on 408 rock specimens including metamorphic rocks, sedimentary rocks and igneous rocks. Through the statistical analysis of the laboratory test data, several regression equations among rock material parameters were established. The research suggests that, in addition to Poisson's ratio, the mechanical parameters (unconfined compressive strength (UCS), elastic Young’s modulus, shear modulus) relate well to physical parameters (porosity, P-wave velocity), and the relationships are mainly described by power and exponential correlations which have good squared regression coefficients. The correlation between elastic Young’s modulus and dynamic elastic modulus was established, as well as the relationship between shear modulus and dynamic shear modulus.

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.

Influence of specimen configuration on the measurement of the off-axis Young’s modulus of wood by vibration tests

Holzforschung ◽  
2012 ◽  
Vol 66 (4) ◽  
Author(s):  
Hiroshi Yoshihara
Keyword(s):  
Numerical Analysis ◽  
Young’S Modulus ◽  
Test Data ◽  
Young's Modulus ◽  
Flexural Vibration ◽  
Solid Wood ◽  
Vibration Tests

Abstract To determine the Young’s modulus of solid wood, longitudinal and flexural vibration methods are very effective because the Young’s modulus can be measured non-destructively. When the specimen has an off-axis angle, however, the specimen configuration has an influence on the measurement of Young’s modulus. Therefore, it is important to reveal the influence of specimen configuration on the measurement of off-axis Young’s modulus. In this research, the off-axis Young’s modulus of wood was obtained by conducting longitudinal and flexural vibration tests using specimens with various widths and performing a subsequent numerical analysis on the test data. The off-axis Young’s modulus was dependent on specimen configuration when the off-axis angle ranged from approximately 5° to 15° because the bending and torsional deformations in the longitudinal and flexural vibration tests, respectively, were significant in this range.

Nondestructive Method for the Determination of the Elastic Properties of Welded Aluminum Plates

2015 ◽  
Vol 1111 ◽  
pp. 73-78 ◽  
Author(s):  
Alexandru Perescu ◽  
Liviu Bereteu ◽  
Dorin Simoiu ◽  
Eva Nyaguly
Keyword(s):  
Shear Modulus ◽  
Young’S Modulus ◽  
Elastic Properties ◽  
Young's Modulus ◽  
Nondestructive Method ◽  
Laser Measurements ◽  
Aluminum Plates ◽  
Vibration Tests ◽  
Modern Technologies

The development of modern technologies requires new materials and technologies prepared for specific technical applications. Aluminum is one of these materials, it can be welded and anodized, which gives them anticorrosive characteristics. The determination of mechanical properties (Young’s modulus and shear modulus) is of great importance from both scientific and practical points of view. Most of the known methods for determination of the Young’s modulus and shear modulus are sample destructive and base on measuring a force (energy) necessary for break the sample. This paper presents a nondestructive method for the determination of the elastic properties of welded aluminum plates by vibration tests and laser measurements using Doppler velocimeter. A Fast Fourier Transform algorithm is used for processing the sampled signals.

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