scholarly journals Relationship between Thermal Diffusivity and Mechanical Properties of Wood

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 632
Author(s):  
Yuri I. Golovin ◽  
Alexander I. Tyurin ◽  
Dmitry Yu. Golovin ◽  
Alexander A. Samodurov ◽  
Sergey M. Matveev ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Diffusivity ◽  
Young’S Modulus ◽  
Mechanical Characteristics ◽  
Young's Modulus ◽  
Brinell Hardness ◽  
Mechanical Tests ◽  
Pedunculate Oak ◽  
Young’S Moduli ◽  
Diffusivity Tensor

This paper describes an experimental study of the relationships between thermal diffusivity and mechanical characteristics including Brinell hardness, microhardness, and Young’s modulus of common pine (Pinus sylvestris L.), pedunculate oak (Quercus robur L.), and small-leaf lime (Tilia cordata Mill.) wood. A dependence of Brinell hardness and thermal diffusivity tensor components upon humidity for common pine wood is found. The results of the measurement of Brinell hardness, microhardness, Young’s modulus, and main components of thermal diffusivity tensor for three perpendicular cuts are found to be correlated. It is shown that the mechanical properties correlate better with the ratio of longitude to transversal thermal diffusivity coefficients than with the respective individual absolute values. The mechanical characteristics with the highest correlation with the abovementioned ratio are found to be the ratio of Young’s moduli in longitude and transversal directions. Our technique allows a comparative express assessment of wood mechanical properties by means of a contactless non-destructive measurement of its thermal properties using dynamic thermal imaging instead of laborious and material-consuming destructive mechanical tests.

Mechanical properties and toughening mechanisms of epoxy/graphene nanocomposites

2015 ◽  
Vol 35 (3) ◽  
pp. 257-266 ◽  
Author(s):  
Rahim Eqra ◽  
Kamal Janghorban ◽  
Habib Daneshmanesh
Keyword(s):  
Mechanical Properties ◽  
Fracture Surface ◽  
Flexural Strength ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Graphene Nanosheets ◽  
Flexural Modulus ◽  
Mechanical Tests ◽  
Toughening Mechanism ◽  
Graphene Nanocomposites

Abstract Because of extraordinary physical, chemical and mechanical properties, graphene nanosheets (GNS) are suitable fillers for optimizing the properties of different polymers. In this research, the effect of GNS content (up to 1 wt.%) on tensile and flexural properties, morphology of fracture surface, and toughening mechanism of epoxy were investigated. Results of mechanical tests showed a peak for tensile and flexural strength of samples with 0.1 wt.% GNS such that the tensile and flexural strength improved by 13% and 3.3%, respectively. The Young’s modulus and flexural modulus increased linearly with GNS content, although the behavior of the Young’s modulus was more remarkable. Morphological investigations confirmed this behavior because the GNS dispersion in the epoxy matrix was uniform at lower contents and agglomerated at higher contents. Finally, microscopical observation showed that the major toughening mechanism of graphene-epoxy nanocomposites was crack path deflection, which changed the mirror fracture surface of the pure epoxy to rough surface.

Evaluation of Mechanical Properties of Regenerated Bone by Nanoindentation Technique

2010 ◽  
Vol 654-656 ◽  
pp. 2220-2224 ◽  
Author(s):  
Takuya Ishimoto ◽  
Takayoshi Nakano
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Bone Tissue ◽  
Material Properties ◽  
Mechanical Performance ◽  
Young's Modulus ◽  
Mechanical Tests ◽  
Long Bone ◽  
Nanoindentation Technique ◽  
Intact Bone

To evaluate the material parameters of regenerated bone, it is important to clarify the mechanical performance of the regenerated portion. In general, the shape and size of regenerated bone tissue is heterogeneous. It is often difficult to elucidate material properties by means of conventional mechanical tests such as compressive and/or tensile tests and bending tests. The nanoindentation technique has been utilized to evaluate the material properties of small or microstructured materials because they do not necessarily require a large well-designed specimen. Thus, this technique may be useful for the evaluation of the material properties of regenerated bone tissue. In this study, this technique was applied for the assessment of the Young’s modulus and hardness of regenerated and intact long bones of a rabbit. The regenerated bone exhibited a significantly lower Young’s modulus and hardness than the intact bone. The regenerated long bone also exhibited impaired mechanical properties, which may have been caused by the difference in the nano-organization of its collagen fibers and mineral crystals (the main components of bone tissue), from that of the intact bone.

Mechanical Properties Of Cu-Based Composites with in Situ Formed Ultrafine Filaments

1981 ◽  
Vol 12 ◽  
Author(s):  
J. Bevk ◽  
W. A. Sunder ◽  
G. Dublon ◽  
David E. Cohen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Young’S Modulus ◽  
Size Dependence ◽  
Young's Modulus ◽  
Plastic Properties ◽  
Young’S Moduli ◽  
Lattice Softening

ABSTRACTElastic and plastic properties of in situ Cu-based composites with Nb, V, and Fe filaments are reviewed. The evidence is presented for a pronounced size dependence of both the ultimate tensile strength and the Young's moduli. In composites with the smallest filaments (d∼50–200Å) and filament densities as high as 1010/cm2 dislocation density reaches values of 1013 cm/cm3. The yield stress of these samples increases dramatically over the predictions based on the “rule of mixtures” and their ultimate tensile strength approaches the estimated theoretical strength of the material (∼2.7GPa). The observed decrease of Young's modulus as a function of inverse wire diameter in the as-drawn composites is attributed to lattice softening due to high density of extended lattice defects. Upon annealing, Young's modulus increases by as much as 100% and exceeds the maximum values calculated from bulk elastic constants. Possible mechanisms leading to modulus enhancement and to related changes in magnetic and superconducting behavior of in situ composites are discussed.

Effects of Hydrogen Absorption on the Mechanical Properties of Zr-Nb Alloys

2007 ◽  
Vol 1043 ◽  
Author(s):  
Shunichiro Nishioka ◽  
Masato Ito ◽  
Hiroaki Muta ◽  
Masayoshi Uno ◽  
Shinsuke Yamanaka
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Young’S Modulus ◽  
Hydrogen Content ◽  
Hydrogen Absorption ◽  
Room Temperature ◽  
Young's Modulus ◽  
Characteristic Vibration ◽  
Young’S Moduli ◽  
Vibration Technique

AbstractYoung's moduli of hydrogenated Zr-Nb alloys were evaluated by using a multiple elastometer in the temperature range from room temperature to 773 K, based on the cantilever characteristic vibration technique. The decreasing rate of Young's modulus against the temperature was independent on the additive amount of Nb. The Young's modulus for the hydrogen solid solution of Zr-Nb alloys decreased and that those for the alloys with partially precipitated hydride slightly changed with increasing hydrogen content in both of Zr-1.0Nb and Zr-2.5Nb. The decreasing rates with hydrogen content of hydrogen solid solution of Zr-Nb alloys were almost same as that of Zr hydrogen solid solution. This result was considered because all specimens largely consisted of α-zirconium in which the solute hydrogen was found to decrease the Young's modulus.

Effect of mineralogy and organic matter on mechanical properties of shale

2015 ◽  
Vol 3 (3) ◽  
pp. SV9-SV15 ◽  
Author(s):  
Vikas Kumar ◽  
Carl Sondergeld ◽  
Chandra S. Rai
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Clay Content ◽  
Organic Content ◽  
Small Samples ◽  
Quartz Content ◽  
Eagle Ford ◽  
Young’S Moduli ◽  
Heterogeneous Samples

We report a nanoindentation study of shales on 144 samples from Barnett, Eagle Ford, Haynesville, Kimmeridge, Ordovician, and Woodford plays. Mineralogy is found to play an important role in controlling mechanical properties of shales: An increase in carbonate and quartz content is correlated with an increase in Young’s modulus, whereas an increase in total organic content, clay content, and porosity decreases Young’s modulus. We had a close agreement between indentation moduli measured on small samples (millimeter scale) and dynamic moduli calculated from velocity and density measurements made on larger samples (centimeter scale). By taking an average of a large number of indentation Young’s moduli, 100 indentations in our case, and using an appropriate penetration force, nanoindentation technology measured an acceptable average Young’s modulus even for heterogeneous samples such as shale highlighting the potential of applying this technology to plug and perhaps field-scale problems.

scholarly journals Microscopic mechanism of sandstone hydration in Yungang Grottoes, China

2020 ◽  
Vol 12 (1) ◽  
pp. 598-609
Author(s):  
Jiawei Chen ◽  
Jinming Xu ◽  
Jizhong Huang
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Open Data ◽  
Physical And Mechanical Properties ◽  
Engineering Properties ◽  
Microscopic Mechanism ◽  
Data Set ◽  
Young’S Moduli ◽  
Yungang Grottoes

AbstractThe macroscopic engineering properties of sandstone are dominated primarily by mineral features in a microscopic scale. This study will investigate the microscopic physical and mechanical properties of the main minerals (quartz, K-feldspar, Na-feldspar and kaolinite) in Yungang Grottoes sandstone, using the molecular mechanics and the molecular dynamics simulations. The microscopic physical properties were represented by density and volume. The microscopic mechanical properties were represented by Young’s modulus and Poisson’s ratio. The microscopic mechanical properties of the minerals in various directions were then explored. The influences of water molecules and the surrounding temperature on the microscopic physical and mechanical properties of the minerals were furthermore investigated. It is found that the differences in the microscopic densities between the simulated results and those from the open data set are, respectively, 0.37%, 1.15% and 9.16%, for the quartz, Na-feldspar and kaolinite cells; the microscopic mechanical properties of various minerals have a significant anisotropy; the Young’s modulus of halloysite decreases by 75.86% compared with that of kaolinite; as the water molecule number increased from 0 to 5, the Young’s moduli of K-feldspar, Na-feldspar and kaolinite cells decreases by 31.31%, 55.05% and 42.60%, respectively; for each mineral, as the temperature increases from 243.15 to 303.15 K under one atmospheric pressure, the volume increases and the density decreases. Those results may have a theoretical significance for the analysis of microscopic mechanism of hydration in the Yungang Grottoes sandstone.

scholarly journals Simultaneous Modeling of Young’s Modulus, Yield Stress, and Rupture Strain of Gelatin/Cellulose Acetate Microfibrous/Nanofibrous Scaffolds Using RSM

2021 ◽  
Vol 9 ◽  
Author(s):  
Alireza Barazesh ◽  
Mahdi Navidbakhsh ◽  
Ali Abouei Mehrizi ◽  
Mojtaba Koosha ◽  
Sajad Razavi Bazaz ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cellulose Acetate ◽  
Yield Stress ◽  
Young’S Modulus ◽  
Mechanical Characteristics ◽  
Rotation Speed ◽  
Young's Modulus ◽  
Structural Parameters ◽  
Weight Ratio ◽  
Wide Range

Electrospinning is a promising method to fabricate bioengineered scaffolds, thanks to utilizing various types of biopolymers, flexible structures, and also the diversity of output properties. Mechanical properties are one of the major components of scaffold design to fabricate an efficacious artificial substitute for the natural extracellular matrix. Additionally, fiber orientations, as one of the scaffold structural parameters, could play a crucial role in the application of fabricated fibrous scaffolds. In this study, gelatin was used as a highly biocompatible polymer in blend with cellulose acetate (CA), a polysaccharide, to enhance the achievable range of mechanical characteristics to fabricated fibrous electrospun scaffolds. By altering input variables, such as polymers concentration, weight ratio, and mandrel rotation speed, scaffolds with various mechanical and morphological properties could be achieved. As expected, the electrospun scaffold with a higher mandrel rotation speed shows higher fiber alignment. A wide range of mechanical properties were gained through different values of polymer ratio and total concentration. A general improvement in mechanical strength was observed by increasing the concentration and CA content in the solution, but contradictory effects, such as high viscosity in more concentrated solutions, influenced the mechanical characteristics as well. A response surface method was applied on experimental results in order to describe a continuous variation of Young’s modulus, yield stress, and strain at rupture. A full quadratic version of equations with the 95% confidence level was applied for the response modeling. This model would be an aid for engineers to adjust mandrel rotation speed, solution concentration, and gelatin/CA ratio to achieve desired mechanical and structural properties.

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.

scholarly journals Potential Bone Replacement Materials Prepared by Two Methods

2012 ◽  
Vol 1418 ◽  
Author(s):  
Steve Lee ◽  
Michael Porter ◽  
Scott Wasko ◽  
Grace Lau ◽  
Po-Yu Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Cancellous Bone ◽  
Young's Modulus ◽  
Pore Sizes ◽  
Young’S Moduli ◽  
Bone Replacement ◽  
Synthetic Scaffolds ◽  
Synthetic Hydroxyapatite ◽  
Natural And Synthetic

ABSTRACTNatural and synthetic hydroxyapatite (HA) scaffolds for potential load-bearing bone implants were fabricated by two methods. The natural scaffolds were formed by heating bovine cancellous bone at 1325°C, which removed the organic and sintered the HA. The synthetic scaffolds were prepared by freeze-casting HA powders, using different solid loadings (20–35 vol.%) and cooling rates (1–10°C/min). Both types of scaffolds were infiltrated with polymethylmethacrylate (PMMA). The porosity, pore size, and compressive mechanical properties of the natural and synthetic scaffolds were investigated and compared to that of natural cortical and cancellous bone. Prior to infiltration, the sintered cancellous scaffolds exhibited pore sizes of 100 – 300 μm, a strength of 0.4 – 9.7 MPa, and a Young’s modulus of 0.1 – 1.2 GPa. The freeze-casted scaffolds had pore sizes of 10 – 50 μm, strengths of 0.7 – 95.1 MPa, and Young’s moduli of 0.1 –19.2 GPa. When infiltrated with PMMA, the cancellous bone- PMMA composite showed a strength of 55 MPa and a Young’s modulus of 4.5 GPa. Preliminary data for the synthetic HA-PMMA composite showed a strength of 42 MPa and a modulus of 0.8 GPa.

Effect of Y2O3 on Mechanical Properties of Ti-29Nb-13Ta-4.6Zr for Biomedical Applications

2010 ◽  
Vol 654-656 ◽  
pp. 2138-2141 ◽  
Author(s):  
Xiu Song ◽  
Mitsuo Niinomi ◽  
Harumi Tsutsumi ◽  
Toshikazu Akahori ◽  
Masaaki Nakai ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Young’S Modulus ◽  
Biomedical Applications ◽  
Mechanical Performance ◽  
Young's Modulus ◽  
Good Balance ◽  
Young’S Moduli ◽  
Β Phase

Y2O3 was added to β-type Ti-29Nb-13Ta-4.6Zr (TNTZ) in order to achieve excellent mechanical performance and low Young’s modulus. TNTZ specimens with 0.05%–1.0% Y are all found to be composed of a β phase. Young’s moduli of TNTZ with 0.05–1.0% Y are all maintained low, and are almost the same as that of TNTZ without Y2O3. The grain size of TNTZ with 0.05%–1.0% Y is smaller than that of TNTZ without Y2O3. Moreover, Y2O3 precipitates can prevent the texture movement, and this effect becomes more obvious with an increase in the Y concentration. The tensile strength of TNTZ is successfully improved by adding Y2O3. TNTZ specimens with 0.2% and 1.0% Y exhibit good balance between the tensile strength and the elongation.

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