scholarly journals Determination of the Young’s Modulus and Shear Modulus of Solid Wood by the Symmetric and Asymmetric Four-Point Bending Tests

2020 ◽  
Vol 69 (6) ◽  
pp. 429-433
Author(s):  
Hiroshi YOSHIHARA ◽  
Masahiro YOSHINOBU ◽  
Makoto MARUTA
Keyword(s):  
Shear Modulus ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Solid Wood ◽  
Bending Tests ◽  
Four Point Bending

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.

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.

scholarly journals MEASURMENT OF BENDING PROPERTIES OF RHIZOPHORA TROPICAL WOOD

2017 ◽  
Vol 27 (2) ◽  
pp. 73-84
Author(s):  
Sinin Hamdan ◽  
Mahbub Hasan ◽  
Yoann Nohe
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Bending Test ◽  
Proportional Limit ◽  
Bending Properties ◽  
Bending Tests ◽  
Four Point Bending ◽  
Limit Stress ◽  
Four Point Bending Test ◽  
Proportional Limit Stress

The Young’s modulus, load at the yield point and proportional limit stress from the compression bending (cb) test were compared with the four point bending tests (4pb). The theoretical Young’s modulus are larger than the real reading for 5mm and 10mm thick specimens, except for 200mm long specimens due to specimen nonlinearity. The experimental results for the short specimens are slightly high compared to the theory due to uniaxial compression in both tensile and compressive planes. Since the additional deflection produced by the shearing force and the stress concentration at the loading point was smaller with the compression bending test compared to the conventional four point bending test the values of Ecb are larger than E4pb. It is noted that when length/thickness (l/t)>80, the values of Ecb are scattered. In addition, Ecb decrease sharply when l/t<30. In order to obtain a stable Young’s modulus value, it is suggested that the l/t should be 30~80.

scholarly journals Determination of Young’s modulus of Sb2S3 nanowires by in situ resonance and bending methods

2016 ◽  
Vol 7 ◽  
pp. 278-283 ◽  
Author(s):  
Liga Jasulaneca ◽  
Raimonds Meija ◽  
Alexander I Livshits ◽  
Juris Prikulis ◽  
Subhajit Biswas ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Cross Section ◽  
Young's Modulus ◽  
Cross Sectional ◽  
Bending Tests ◽  
Young’S Moduli ◽  
Increasing Trend

In this study we address the mechanical properties of Sb2S3 nanowires and determine their Young’s modulus using in situ electric-field-induced mechanical resonance and static bending tests on individual Sb2S3 nanowires with cross-sectional areas ranging from 1.1·104 nm2 to 7.8·104 nm2. Mutually orthogonal resonances are observed and their origin explained by asymmetric cross section of nanowires. The results obtained from the two methods are consistent and show that nanowires exhibit Young’s moduli comparable to the value for macroscopic material. An increasing trend of measured values of Young’s modulus is observed for smaller thickness samples.

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.

scholarly journals Measurment of bending properties of rhizophora tropical wood

2017 ◽  
Vol 26 (2) ◽  
pp. 73-84
Author(s):  
Sinin Hamdan ◽  
Mahbub Hasan ◽  
Yoann Nohe
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Bending Test ◽  
Proportional Limit ◽  
Bending Properties ◽  
Bending Tests ◽  
Four Point Bending ◽  
Limit Stress ◽  
Four Point Bending Test ◽  
Proportional Limit Stress

The Young’s modulus, load at the yield point and proportional limit stress from the compression bending (cb) test were compared with the four point bending tests (4pb). The theoretical Young’s modulus are larger than the real reading for 5mm and 10mm thick specimens, except for 200mm long specimens due to specimen nonlinearity. The experimental results for the short specimens are slightly high compared to the theory due to uniaxial compression in both tensile and compressive planes. Since the additional deflection produced by the shearing force and the stress concentration at the loading point was smaller with the compression bending test compared to the conventional four point bending test the values of Ecb are larger than E4pb. It is noted that when length/thickness (l/t)>80, the values of Ecb are scattered. In addition, Ecb decrease sharply when l/t<30. In order to obtain a stable Young’s modulus value, it is suggested that the l/t should be 30~80.

Is it necessary to calculate Young’s modulus in AFM nanoindentation experiments regarding biological samples?

2020 ◽  
Vol 12 ◽  
Author(s):  
S.V. Kontomaris ◽  
A. Malamou ◽  
A. Stylianou
Keyword(s):  
Young’S Modulus ◽  
Biological Samples ◽  
Young's Modulus ◽  
Reference Sample ◽  
Nonlinear Behavior ◽  
Accurate Method ◽  
Accurate Solution ◽  
Hertz Model ◽  
Work Done

Background: The determination of the mechanical properties of biological samples using Atomic Force Microscopy (AFM) at the nanoscale is usually performed using basic models arising from the contact mechanics theory. In particular, the Hertz model is the most frequently used theoretical tool for data processing. However, the Hertz model requires several assumptions such as homogeneous and isotropic samples and indenters with perfectly spherical or conical shapes. As it is widely known, none of these requirements are 100 % fulfilled for the case of indentation experiments at the nanoscale. As a result, significant errors arise in the Young’s modulus calculation. At the same time, an analytical model that could account complexities of soft biomaterials, such as nonlinear behavior, anisotropy, and heterogeneity, may be far-reaching. In addition, this hypothetical model would be ‘too difficult’ to be applied in real clinical activities since it would require very heavy workload and highly specialized personnel. Objective: In this paper a simple solution is provided to the aforementioned dead-end. A new approach is introduced in order to provide a simple and accurate method for the mechanical characterization at the nanoscale. Method: The ratio of the work done by the indenter on the sample of interest to the work done by the indenter on a reference sample is introduced as a new physical quantity that does not require homogeneous, isotropic samples or perfect indenters. Results: The proposed approach, not only provides an accurate solution from a physical perspective but also a simpler solution which does not require activities such as the determination of the cantilever’s spring constant and the dimensions of the AFM tip. Conclusion: The proposed, by this opinion paper, solution aims to provide a significant opportunity to overcome the existing limitations provided by Hertzian mechanics and apply AFM techniques in real clinical activities.

scholarly journals Apparent Young’s Modulus of the Adhesive in Numerical Modeling of Adhesive Joints

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 328
Author(s):  
Kamil Anasiewicz ◽  
Józef Kuczmaszewski
Keyword(s):  
Numerical Model ◽  
Young’S Modulus ◽  
Adhesive Joint ◽  
Young's Modulus ◽  
Precise Determination ◽  
Adhesive Joints ◽  
Experimental Conditions ◽  
Element Simulation ◽  
Joint Material

This article is an evaluation of the phenomena occurring in adhesive joints during curing and their consequences. Considering changes in the values of Young’s modulus distributed along the joint thickness, and potential changes in adhesive strength in the cured state, the use of a numerical model may make it possible to improve finite element simulation effects and bring their results closer to experimental data. The results of a tensile test of a double overlap adhesive joint sample, performed using an extensometer, are presented. This test allowed for the precise determination of the shear modulus G of the cured adhesive under experimental conditions. Then, on the basis of the research carried out so far, a numerical model was built, taking the differences observed in the properties of the joint material into account. The stress distribution in a three-zone adhesive joint was analyzed in comparison to the standard numerical model in which the adhesive in the joint was treated as isotropic. It is proposed that a joint model with three-zones, differing in the Young’s modulus values, is more accurate for mapping the experimental results.

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