Effect of specimen configuration and orthotropy on the Young’s modulus of solid wood obtained from a longitudinal vibration test

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Hiroshi Yoshihara ◽  
Makoto Maruta
Keyword(s):  
Young’S Modulus ◽  
Transverse Direction ◽  
Young's Modulus ◽  
Longitudinal Vibration ◽  
Longitudinal Direction ◽  
Solid Wood ◽  
Western Hemlock ◽  
Width Ratio ◽  
Vibration Test ◽  
Length Width

AbstractYoung’s modulus in the longitudinal direction was measured by a longitudinal vibration (LV) test on western hemlock specimens with various length/width ratios. The effects of the configuration and orthotropy of the specimen on the measurement of Young’s modulus was investigated through subsequent finite element (FE) calculations. The experimental results suggested that Young’s modulus could not be obtained accurately when the length/width ratio of the specimen was in a certain range. The FE calculations revealed that Young’s modulus in the transverse direction and Poisson’s ratio in the length-width plane, as well as the length/width ratio, affected the Young’s modulus value. However, the results showed that when the length/width ratio of the specimen was larger than 10, Young’s modulus could be measured accurately with the LV test with a reduction in the effect of orthotropy.

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.

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.

Inferring Physical Parameters from Images of Vibrating Carbon Nanotubes

2000 ◽  
Vol 6 (4) ◽  
pp. 317-323 ◽  
Author(s):  
M.M.J. Treacy ◽  
A. Krishnan ◽  
P.N. Yianilos
Keyword(s):  
Carbon Nanotubes ◽  
Young’S Modulus ◽  
Shot Noise ◽  
Vibration Amplitude ◽  
Young's Modulus ◽  
Single Wall Carbon Nanotubes ◽  
Physical Parameters ◽  
Average Value ◽  
Length Width ◽  
Hidden Parameter

Abstract We describe a hidden parameter inferencing algorithm for deducing the length, width, and vibration profile from images of thermally excited single-wall carbon nanotubes. With accurate estimates of these parameters, the Young’s modulus can be deduced. The algorithm is sensitive to shot noise in the image, primarily because of the low nanotube image contrast. Noise causes the nanotube length and width to be overestimated, and the vibration amplitude to be underestimated. After correcting for shot noise, we infer an average value of the Young’s modulus of 〈Y〉= 1.20±0.20 TPa, which is larger than the currently accepted value for graphite.

Study on Regeneration Pre-Sensitized Offset Plate Based on the Nondestructive Testing Method

2011 ◽  
Vol 380 ◽  
pp. 348-351 ◽  
Author(s):  
Jiang Chang ◽  
Xue Gong ◽  
Zhi Hui Sun
Keyword(s):  
Nondestructive Testing ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Longitudinal Vibration ◽  
Flexural Vibration ◽  
Vibration Method ◽  
Testing Method ◽  
Dynamic Young’S Modulus ◽  
Dynamic Young's Modulus ◽  
Nondestructive Testing Method

In this paper the vibration testing and Fast Fourier Transform(FFT) analysis detection on the basis of nondestructive testing method were analyzed. The dynamic Young’s modulus of the regeneration pre-sensitized offset plate were obtained by using the nondestructive testing methods, including the dynamic Young’s modulus by longitudinal vibration method, the dynamic Young’s modulus by out-plane flexural vibration method, and the dynamic Young’s modulus by in-plane flexural vibration method. The linear correlativity was investigated between the dynamic Young’s modulus and the modulus of elasticity(MOE) for the regeneration pre-sensitized offset plate.The linear correlations between the dynamic Young’s modulus and the MOE were good. So it is feasible to predict and analyze the plate mechanical properties put forward the nondestructive testing method of key mechanical performance parameters.

Longitudinal vibration wave in the composite elastic metamaterials containing Bragg structure and local resonator

2020 ◽  
Vol 34 (26) ◽  
pp. 2050232
Author(s):  
Xiaofei Lei ◽  
Peng Chen ◽  
Heping Hou ◽  
Shanhui Liu ◽  
Peng Liu
Keyword(s):  
Mathematical Model ◽  
Young’S Modulus ◽  
Transmission Spectrum ◽  
Strain Energy ◽  
Young's Modulus ◽  
Dynamic Properties ◽  
Longitudinal Vibration ◽  
Total Width ◽  
Bragg Structure ◽  
Vibration Wave

In this paper, a novel composite acoustical hyperstructure of Bragg structure with local resonator is investigated theoretically for discussing the scattering performance of longitudinal vibration wave, its bandgaps are calculated using the established mathematical model. For confirming the veritable existence of bandgap and verifying the correctness of established mathematical model, the transmission spectrum of composite acoustical hyperstructure is also studied using finite-element method, and comparing the vibration transmission spectrum with bandgaps, the results indicate that the established theoretical model can correctly predict longitudinal wave bandgaps. Moreover, the bandgaps and modes shapes are calculated and compared with an unalloyed Bragg structure for probing the dispersion mechanics of composite acoustical hyperstructure, it turned out that local resonator can add one bandgap at the base of Bragg structure and the total bandgaps can be broadened. Further, for discussing the effect of spring of local resonator on bandgaps, bandgap of local resonator with different spring is calculated, the results showed that the total width of BG is larger when Young’s modulus is 1E and 16E, the total width are 772.48 and 774.30 Hz, respectively; as Young’s modulus is 0.5E and 2E, the width of BG are lower, 753.79 and 754.23 Hz, respectively. In view of longitudinal vibration wave inducing structural distortion and vibration energy conversion, the dynamic properties of composite acoustical hyperstructure are studied via strain energy density, the results indicate that reaction formation of local resonator can dissipate strain energy, when the local resonator is not activated (or waveless along with Bragg structure), un-dissipation strain energy.

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