Young’s and shear moduli of glued laminated timber composed of different species obtained by a flexural vibration test

Holzforschung ◽  
2012 ◽  
Vol 66 (7) ◽  
pp. 871-875 ◽  
Author(s):  
Yoshitaka Kubojima ◽  
Mario Tonosaki
Keyword(s):  
Elastic Constants ◽  
Pinus Densiflora ◽  
Flexural Vibration ◽  
Japanese Cedar ◽  
Picea Sitchensis ◽  
Vibration Test ◽  
Shear Moduli ◽  
Glued Laminated Timber ◽  
Flexural Vibration Test ◽  
Lamination Theory

Abstract The applicability of the flexural vibration test to determine the elastic constants of glued laminated timber (GLT) composed of five wood species (ash, Fraxinus spaethiana Lingelsh.; balsa, Ochroma pyramidale Urban.; Japanese cedar, Cryptomeria japonica D. Don; Japanese red pine, Pinus densiflora Sieb. et Zucc.; Sitka spruce, Picea sitchensis Carr.) has been investigated. GLT models were prepared from four laminae with dimensions of 30 (R)×5 (T)×300 (L) mm3. The suitability of Japanese cedar for inner layers in GLTs was tested by flexural vibration test to determine the elastic constants of the laminae and the glued laminated timber. The Young’s and shear moduli were calculated by the Goens-Hearmon regression method based on the Timoshenko theory of bending (TGH method), and the results were compared with the estimated values based on the Young’s and shear moduli measured individually of each lamina. The simple lamination theory was found to be applicable for Young’s modulus but not to shear modulus. The result obtained based on the lamination theory from the shear strain energy was similar to that obtained by the TGH method.

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.

Shear modulus of several kinds of Japanese bamboo obtained by flexural vibration test

2009 ◽  
Vol 56 (1) ◽  
pp. 64-70 ◽  
Author(s):  
Yoshitaka Kubojima ◽  
Yoko Inokuchi ◽  
Youki Suzuki ◽  
Mario Tonosaki
Keyword(s):  
Shear Modulus ◽  
Flexural Vibration ◽  
Vibration Test ◽  
Flexural Vibration Test

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.

First-Principle Investigation of Structural, Elastic, Electronic and Thermal Properties of Dysprosium Hafnate Oxides

2018 ◽  
Author(s):  
Hui Niu
Keyword(s):  
Thermal Properties ◽  
Elastic Constants ◽  
Density Functional ◽  
Functional Theory ◽  
Shear Moduli ◽  
Charge Densities ◽  
Young’S Moduli ◽  
Densities Of States ◽  
Complete Set ◽  
The Mean

Systematic first-principles calculations based on density functional theory were performed on Dy2HfxO3+2x (x = 0, 1, and 2) compositions. A complete set of elastic parameters including elastic constants, Hill’s bulk moduli, Young’s moduli, shear moduli and Poisson’s ratio were calculated. Analyses of densities of states and charge densities and electron localization functions suggest that the oxide bonds are highly ionic with some degree of covalency in the Hf-O bonds. Thermal properties including the mean sound velocity, Debye temperature, and minimum thermal conductivity were obtained from the elastic constants.

scholarly journals Flexural Vibration Test of a Beam Elastically Restrained at One End: A New Approach for Young’s Modulus Determination

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Rafael M. Digilov ◽  
Haim Abramovich
Keyword(s):  
Young Modulus ◽  
Flexural Vibration ◽  
Force Sensor ◽  
Frequency Equation ◽  
Bending Vibrations ◽  
Flexural Vibration Test ◽  
Elastically Restrained ◽  
Fixed End ◽  
Partially Restrained

A new vibration beam technique for the fast determination of the dynamic Young modulus is developed. The method is based on measuring the resonant frequency of flexural vibrations of a partially restrained rectangular beam. The strip-shaped specimen fixed at one end to a force sensor and free at the other forms the Euler Bernoulli cantilever beam with linear and torsion spring on the fixed end. The beam is subjected to free bending vibrations by simply releasing it from a flexural position and its dynamic response detected by the force sensor is processed by FFT analysis. Identified natural frequencies are initially used in the frequency equation to find the corresponding modal numbers and then to calculate the Young modulus. The validity of the procedure was tested on a number of industrial materials by comparing the measured modulus with known values from the literature and good agreement was found.

Moderately Thick Angle-Ply Cylindrical Shells Under Internal Pressure

1989 ◽  
Vol 56 (3) ◽  
pp. 652-657 ◽  
Author(s):  
Kamal R. Abu-Arja ◽  
Reaz A. Chaudhuri
Keyword(s):  
Internal Pressure ◽  
Cylindrical Shells ◽  
Shear Deformation Theory ◽  
Shear Angle ◽  
Shear Moduli ◽  
Closed Form Solutions ◽  
First Order ◽  
Constant Shear ◽  
Lamination Theory ◽  
Limiting Case

Heretofore unavailable closed-form solutions are obtained for unbalanced symmetric as well as balanced unsymmetric angle-ply, moderately thick cylindrical shells subjected to axially varying (axisymmetric) internal pressure loading, under the framework of constant shear-angle theory (CST) or first-order shear deformation theory (FSDT), for any boundary condition. The solutions are obtained for four CST-based kinematic relations, which are extensions of the classical shell theories due to Donnell, Love-Timoshenko, Love-Riessner, and Sanders. The available CLT (classical lamination theory)-based solutions can be obtained from the present solutions in the limiting case of the two transverse shear moduli tending to infinity. Numerical results have been presented for two layer and three layer angle-ply cylindrical shells with simply-supported edges and have been compared with the corresponding CLT-based analytical solutions and also the LCST (layerwise constant shear angle theory)-based finite element solutions.

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