Elastic properties of carbon nanoscrolls

RSC Advances ◽  
2014 ◽  
Vol 4 (44) ◽  
pp. 22995-23001 ◽  
Author(s):  
Mohammad Mahdi Zaeri ◽  
Saeed Ziaei-Rad
Keyword(s):  
Elastic Properties ◽  
Structural Mechanics ◽  
Geometrical Parameters ◽  
Shear Moduli ◽  
Carbon Nanoscrolls

Young's and shear moduli of carbon nanoscroll obtained through molecular structural mechanics considering various geometrical parameters.

scholarly journals Modelling the elastic mechanical properties of bioactive glass-derived scaffolds

2020 ◽  
Vol 6 (1) ◽  
pp. 50-56
Author(s):  
Francesco Baino ◽  
Elisa Fiume
Keyword(s):  
Elastic Properties ◽  
Poisson’S Ratio ◽  
Mechanical Performance ◽  
Solid Material ◽  
Poisson's Ratio ◽  
Predictive Capability ◽  
Shear Moduli ◽  
Wide Range ◽  
Constitutive Parameters ◽  
The Relationship

AbstractPorosity is known to play a pivotal role in dictating the functional properties of biomedical scaffolds, with special reference to mechanical performance. While compressive strength is relatively easy to be experimentally assessed even for brittle ceramic and glass foams, elastic properties are much more difficult to be reliably estimated. Therefore, describing and, hence, predicting the relationship between porosity and elastic properties based only on the constitutive parameters of the solid material is still a challenge. In this work, we quantitatively compare the predictive capability of a set of different models in describing, over a wide range of porosity, the elastic modulus (7 models), shear modulus (3 models) and Poisson’s ratio (7 models) of bioactive silicate glass-derived scaffolds produced by foam replication. For these types of biomedical materials, the porosity dependence of elastic and shear moduli follows a second-order power-law approximation, whereas the relationship between porosity and Poisson’s ratio is well fitted by a linear equation.

scholarly journals High-Temperature Elastic Properties of Yttrium-Doped Barium Zirconate

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 968
Author(s):  
Fumitada Iguchi ◽  
Keisuke Hinata
Keyword(s):  
High Temperature ◽  
Young’S Modulus ◽  
Elastic Properties ◽  
Measurement Method ◽  
Young's Modulus ◽  
Barium Zirconate ◽  
Shear Moduli ◽  
Ceramic Fuel ◽  
Yttrium Concentration ◽  
Ceramic Fuel Cells

The elastic properties of 0, 10, 15, and 20 mol% yttrium-doped barium zirconate (BZY0, BZY10, BZY15, and BZY20) at the operating temperatures of protonic ceramic fuel cells were evaluated. The proposed measurement method for low sinterability materials could accurately determine the sonic velocities of small-pellet-type samples, and the elastic properties were determined based on these velocities. The Young’s modulus of BZY10, BZY15, and BZY20 was 224, 218, and 209 GPa at 20 °C, respectively, and the values decreased as the yttrium concentration increased. At high temperatures (>20 °C), as the temperature increased, the Young’s and shear moduli decreased, whereas the bulk modulus and Poisson’s ratio increased. The Young’s and shear moduli varied nonlinearly with the temperature: The values decreased rapidly from 100 to 300 °C and gradually at temperatures beyond 400 °C. The Young’s modulus of BZY10, BZY15, and BZY20 was 137, 159, and 122 GPa at 500 °C, respectively, 30–40% smaller than the values at 20 °C. The influence of the temperature was larger than that of the change in the yttrium concentration.

Structural, electronic and elastic properties of Ti2TlC, Zr2TlC and Hf2TlC

Open Physics ◽  
2009 ◽  
Vol 7 (4) ◽  
Author(s):  
Abdelmadjid Bouhemadou
Keyword(s):  
Elastic Properties ◽  
Finite Strain ◽  
High Pressures ◽  
Applied Pressure ◽  
First Principle ◽  
Shear Moduli ◽  
Lattice Constants ◽  
First Principle Calculations ◽  
Electrical Conductors ◽  
Good Agreement

AbstractUsing First-principle calculations, we have studied the structural, electronic and elastic properties of M2TlC, with M = Ti, Zr and Hf. Geometrical optimization of the unit cell is in good agreement with the available experimental data. The effect of high pressures, up to 20 GPa, on the lattice constants shows that the contractions are higher along the c-axis than along the a axis. We have observed a quadratic dependence of the lattice parameters versus the applied pressure. The band structures show that all three materials are electrical conductors. The analysis of the site and momentum projected densities shows that bonding is due to M d-C p and M d-Tl p hybridizations. The M d-C p bonds are lower in energy and stiffer than M d-Tl p bonds. The elastic constants are calculated using the static finite strain technique. We derived the bulk and shear moduli, Young’s modulus and Poisson’s ratio for ideal polycrystalline M2TlC aggregates. We estimated the Debye temperature of M2TlC from the average sound velocity. This is the first quantitative theoretical prediction of the elastic properties of Ti2TlC, Zr2TlC, and Hf2TlC compounds that requires experimental confirmation.

CALCULATED STRUCTURAL AND ELASTIC PROPERTIES OF M2InC(M=Sc, Ti, V, Zr, Nb, Hf, Ta)

2008 ◽  
Vol 22 (22) ◽  
pp. 2063-2076 ◽  
Author(s):  
A. BOUHEMADOU
Keyword(s):  
Experimental Data ◽  
Theoretical Prediction ◽  
Ab Initio Calculations ◽  
Sound Velocity ◽  
Elastic Properties ◽  
Elastic Constants ◽  
Finite Strain ◽  
Applied Pressure ◽  
Shear Moduli ◽  
Young’S Moduli

Using ab initio calculations, we have studied the structural and elastic properties of M 2 InC , with M = Sc , Ti , V , Zr , Nb , Hf and Ta . Geometrical optimization of the unit cell is in agreement with the available experimental data. We have observed a quadratic dependence of the lattice parameters versus the applied pressure. The elastic constants are calculated using the static finite strain technique. We derived the bulk and shear moduli, Young's moduli and Poisson's ratio for ideal polycrystalline M 2 InC aggregates. We estimated the Debye temperature of M 2 InC from the average sound velocity. This is the first quantitative theoretical prediction of the elastic properties of Sc 2 InC , Ti 2 InC , V 2 InC , Zr 2 InC , Nb 2 InC , Hf 2 InC and Ta 2 InC compounds, and it still awaits experimental confirmation.

Modeling squirt dispersion and attenuation in fluid-saturated rocks using pressure dependency of dry ultrasonic velocities

Geophysics ◽  
2012 ◽  
Vol 77 (3) ◽  
pp. WA157-WA168 ◽  
Author(s):  
Osni Bastos de Paula ◽  
Marina Pervukhina ◽  
Dina Makarynska ◽  
Boris Gurevich
Keyword(s):  
Aspect Ratio ◽  
Elastic Properties ◽  
Elastic Moduli ◽  
Pore Space ◽  
Geometrical Parameters ◽  
Laboratory Measurements ◽  
Significant Linear Trend ◽  
Aspect Ratios ◽  
Pressure Dependency ◽  
Dispersion And Attenuation

Modeling dispersion and attenuation of elastic waves in fluid-saturated rocks due to squirt flow requires the knowledge of a number of geometrical parameters of the pore space, in particular, the characteristic aspect ratio of the pores. These parameters are usually inferred by fitting measurements on saturated rocks to model predictions. To eliminate such fitting and thus make the model more predictive, we propose to recover the geometrical parameters of the pore space from the pressure dependency of elastic moduli on dry samples. Our analysis showed that the pressure dependency of elastic properties of rocks (and their deviation from Gassmann’s prediction) at ultrasonic frequencies is controlled by the squirt flow between equant, stiff, and so-called intermediate pores (with aspect ratios between [Formula: see text]). Such intermediate porosity is expected to close at confining pressures of between 200 and 2000 MPa, and thus cannot be directly obtained from ultrasonic experiments performed at pressures below 50 MPa. However, the presence of this intermediate porosity is inferred from the significant linear trend in the pressure dependency of elastic properties of the dry rock and the difference between the bulk modulus of the dry rock computed for spherical pores and the measured modulus at 50 MPa. Moreover, we can infer the magnitude of the intermediate porosity and its characteristic aspect ratio. Substituting these parameters into the squirt model, we have computed elastic moduli and velocities of the water-saturated rock and compared these predictions against laboratory measurements of these velocities. The agreement is good for a number of clean sandstones, but not unexpectedly worse for a broad range of shaley sandstones. Our predictions showed that dispersion and attenuation caused by the squirt flow between compliant and stiff pores may occur in the seismic frequency band. Confirmation of this prediction requires laboratory measurements of elastic properties at these frequencies.

ELASTIC PROPERTIES AND DEBYE CHARACTERISTIC TEMPERATURE OF PARTIALLY MELTED YBa2Cu3O7−x SUPERCONDUCTOR

1988 ◽  
Vol 02 (09) ◽  
pp. 1111-1117 ◽  
Author(s):  
D.F. LEE ◽  
K. SALAMA
Keyword(s):  
Debye Temperature ◽  
Elastic Properties ◽  
Elastic Constants ◽  
Tetragonal Phase ◽  
Room Temperature ◽  
Characteristic Temperature ◽  
Shear Moduli ◽  
Debye Characteristic Temperature ◽  
Temperature Range ◽  
Free Material

The quasi-isotropic elastic constants are measured in a 85% dense partially melted YBa 2 Cu 3 C 7−x superconductor in the temperature range 80–300 K. The room temperature values of the longitudinal and shear moduli of the void-free material are found to be 168 and 59 GPa respectively, and no decrease in these constants is observed during the transition from normal to superconducting states. The Debye temperature is found to be 426 K which is comparable to that of the tetragonal phase polycrystalline BaTiO 3 (429 K).

scholarly journals Computational Investigation of the Effective Mechanical Behavior for 3D Pre-Buckled Auxetic Lattices

2019 ◽  
Vol 86 (11) ◽  
Author(s):  
Frederic Albertini ◽  
Justin Dirrenberger ◽  
Andrey Molotnikov ◽  
Cyrille Sollogoub
Keyword(s):  
Elastic Properties ◽  
Poisson Ratio ◽  
Periodic Boundary Conditions ◽  
Homogenization Method ◽  
Geometrical Parameters ◽  
Computational Investigation ◽  
Effective Elastic Properties ◽  
Acoustic Damping ◽  
The Past ◽  
Geometric Configurations

Abstract Negative Poisson’s ratio materials, or auxetics, have drawn attention for the past 30 years. The auxetic effect could lead to improved mechanical properties such as acoustic damping, indentation resistance, or crashworthiness. In this work, two 3D auxetic lattices are introduced. Auxeticity is achieved by design through pre-buckling of the lattice struts. The influence of geometrical parameters on the effective elastic properties is investigated using computational homogenization method with periodic boundary conditions. Effective Young’s modulus is 3D mapped to reveal anisotropy and identify spatial orientations of interest. The effective Poisson ratio is computed for various geometric configurations to characterize auxeticity. Finally, the influence of effective elastic properties on energy dissipation under compression is explored for elastoplastic lattices with different loading directions, using finite element simulations. Results suggest that loading 3D auxetic lattices along their stiffest direction maximizes their crashworthiness.

First-Principles Study on Elastic Properties of AlN

2013 ◽  
Vol 821-822 ◽  
pp. 841-844 ◽  
Author(s):  
Xin Tan ◽  
Zhen Yang Xin ◽  
Xue Jie Liu ◽  
Qing Ge Mu
Keyword(s):  
Elastic Properties ◽  
Brittle Material ◽  
First Principles ◽  
Elastic Anisotropy ◽  
Three Dimensional ◽  
Elastic Stiffness ◽  
Wurtzite Structure ◽  
Shear Moduli ◽  
Young’S Moduli ◽  
Zinc Blende

Structural and elastic properties of AlN are investigated by using First-principles. Both of wurtzite and zinc-blende structures are investigated, respectively. The bulk moduli of the wurtzite structure and zinc blende AlN are 194.2GPa and 187GPa, which obtained by the elastic stiffness constants respectively. Shear moduli are 136GPa and 124GPa. Young's moduli are 331GPa and 305GPa. Poisson's ratio and Pugh criterion suggests that both of them are brittle material. The brittleness of wurtzite AlN is higher than that of zinc-blende AlN. The elastic anisotropy of the bulk moduli and shear moduli were discussed. Three-dimensional anisotropic of the young's modulus were analyzed.

Influence of geometrical parameters of screw melt mixing on visco-elastic properties of PC/ABS blends

2010 ◽  
Vol 117 (5) ◽  
pp. 2847-2853 ◽  
Author(s):  
Berenika Hausnerová ◽  
Takeshi Kitano ◽  
Vanda Kuthanová ◽  
Petr Sáha
Keyword(s):  
Elastic Properties ◽  
Geometrical Parameters ◽  
Melt Mixing

Research of the Elastic Properties of Bellows Made in SLS Technology

2014 ◽  
Vol 874 ◽  
pp. 77-81 ◽  
Author(s):  
Czeslaw Kundera ◽  
Tomasz Kozior
Keyword(s):  
Elastic Properties ◽  
Elastic Deformation ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Geometrical Parameters ◽  
Additive Technology ◽  
Coefficient Of Elasticity ◽  
Made In

The article contains the result of studies on the effects of selected geometrical parameters of elastic bellows on their elastic properties. Bellows models were produced with using additive technology, selective laser sintering SLS, where the material used to build models was polyamide PA 2200. Based on the measurements of elastic deformation coefficients of each models bellows were determined. Comparing the results of the measurements there was found a significant effect of the thickness, number of corrugations and their length on the value of the coefficient of elasticity.

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