scholarly journals Thermally Tunable Dynamic and Static Elastic Properties of Hydrogel Due to Volumetric Phase Transition

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1462 ◽  
Author(s):  
Yuqi Jin ◽  
Teng Yang ◽  
Shuai Ju ◽  
Haifeng Zhang ◽  
Tae-Youl Choi ◽  
...  
Keyword(s):  
Phase Transition ◽  
Bulk Modulus ◽  
Young’S Modulus ◽  
Elastic Properties ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Poisson's Ratio ◽  
Solution Temperature ◽  
Temperature Sensitive ◽  
Alginate Hydrogel

The temperature dependence of the mechanical properties of polyvinyl alcohol-based poly n-isopropyl acrylamide (PVA-PNIPAm) hydrogel was studied from the static and dynamic bulk modulus of the material. The effect of the temperature-induced volumetric phase transition on Young’s Modulus, Poisson’s ratio, and the density of PVA-PNIPAm was experimentally measured and compared with a non-thermo-responsive Alginate hydrogel as a reference. An increase in the temperature from 27.5 to 32 °C results in the conventional temperature-dependent de-swelling of the PVA-PNIPAm hydrogel volume of up to 70% at the lower critical solution temperature (LCST). However, with the increase in temperature, the PVA-PNIPAm hydrogel showed a drastic increase in Young’s Modulus and density of PVA-PNIPAm and a corresponding decrease in the Poisson’s ratio and the static bulk modulus around the LCST temperature. The dynamic bulk modulus of the PVA-PNIPAm hydrogel is highly frequency-dependent before the LCST and highly temperature-sensitive after the LCST. The dynamic elastic properties of the thermo-responsive PVA-PNIPAm hydrogel were compared and observed to be significantly different from the thermally insensitive Alginate hydrogel.

scholarly journals On the identification of the eggshell elastic properties under quasistatic compression

2004 ◽  
Vol 52 (5) ◽  
pp. 73-82 ◽  
Author(s):  
Jana Simeonovová ◽  
Jaroslav Buchar
Keyword(s):  
Young’S Modulus ◽  
Elastic Properties ◽  
Elastic Constants ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Poisson's Ratio ◽  
Rotational Shell ◽  
Mutual Comparison ◽  
Quasistatic Loading

The problem of the identification of the elastic properties of eggshell, i.e. the evaluation of the Young's modulus and Poisson's ratio is solved. The eggshell is considered as a rotational shell. The experiments on the egg compression under quasistatic loading have been conducted. During these experiments a strain on the eggshell surface has been recorded. By the mutual comparison between experimental and theoretical values of strains the influence of the elastic constants has been demonstrated.

Elastic Constants of Magnesium Thorium Alloy

1967 ◽  
Vol 89 (1) ◽  
pp. 93-97
Author(s):  
J. R. Asay
Keyword(s):  
Shear Modulus ◽  
Bulk Modulus ◽  
Young’S Modulus ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Longitudinal Velocity ◽  
Shear Velocity ◽  
Polycrystalline Sample ◽  
Poisson's Ratio ◽  
Wave Measurements

The longitudinal and shear wave velocities in a polycrystalline sample of magnesium thorium alloy were measured by a pulse transmission technique as a function of temperature. Temperatures ranged from 25 C to about 350 deg C for longitudinal wave measurements and to about 220 deg C for shear measurements. The resulting velocity data were used to calculate various elastic properties of the material, including Young’s modulus, shear modulus, bulk modulus, and Poisson’s ratio. The resulting least squares fits for these data are: Longitudinal velocity, cl = 5.749 − 3.987 × 10−4T − 1.139 × 10−6T2mm/μsec; shear velocity, ct = 3.108 − 1.421 × 10−4T − 2.588 × 10−6T2mm/μsec; bulk modulus, B = 3.576 × 10″ − 2.744 × 107T + 1.187 × 105T2 dynes/cm2; Young’s modulus, E = 4.435 × 10″ − 1.415 × 107T = 6.037 × 105T2 dynes/cm2; shear modulus, G = 1.716 × 10″ − 7.994 × 106T − 2.619 × 105T2 dynes/cm2; Poisson’s ratio, σ = 0.293 − 6.459 × 10−6T + 3.392 × 10−7T2.

Relaxor Single-Crystal Plates with Nano-Size Ferroelectric Domains Applying to Ultrasonic Prove for Medical Uses

2016 ◽  
Vol 102 ◽  
pp. 57-64
Author(s):  
Toshio Ogawa ◽  
Taiki Ikegaya
Keyword(s):  
Bulk Modulus ◽  
Single Crystal ◽  
Grain Boundaries ◽  
Single Crystals ◽  
Young’S Modulus ◽  
Elastic Constants ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Poisson's Ratio ◽  
Domain Alignment

Sound velocities were measured in relaxor single-crystal plates, included in piezoelectric transducers for medical uses, using an ultrasonic precision thickness gauge with high-frequency pulse generation. The velocities were compared with the ones of piezoelectric ceramics in order to clarify characteristics of the single crystals. Estimating the difference in the sound velocities and elastic constants in the single crystals and ceramics, it was possible to evaluate effects of domain and grain boundaries on elastic constants. Existence of domain boundaries in single crystal affected the decrease in Young’s modulus, rigidity, Poisson’s ratio and bulk modulus. While existence of grain boundaries affected the decrease in Young’s modulus and rigidity, Poisson’s ratio and bulk modulus increased. It was thought these phinomina come from domain alignment by DC poling, and both the boundaries act as to absorb mechanical stress by defects due to the boundaries. In addition, the origin of piezoelectricity in single crystals is caused by low bulk modulus and Poisson’s ratio, and high Young’s modulus and rigidity in comparison with ceramics. On the contrary, the origin of piezoelectricity in ceramics is caused by high Poisson’s ratio by high bulk modulus, and furthermore, low Young’s modulus and rigidity due to domain alignment.

scholarly journals The Geomechanics and the Acoustic Anisotropy of Reservoir Rocks

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Ahmed Zarzor Al-Yaseri
Keyword(s):  
Bulk Modulus ◽  
Young’S Modulus ◽  
Poisson’S Ratio ◽  
Reservoir Characterization ◽  
Young's Modulus ◽  
Petroleum Industry ◽  
Wellbore Stability ◽  
Production Performance ◽  
Acoustic Properties ◽  
Poisson's Ratio

Knowing the mechanical properties (Young’s modulus (E)( , Poisson’s Ratio (ν), Shear Modulus (G), Bulk modulus (K) and compressibility which is the inverse of Bulk modulus) of the rocks involve in a reservoir, are critical factors for reservoir characterization). Those properties affect a wide variety of applications into the petroleum industry; from drilling well planning and execution to production performance (sand production, compaction, subsidence, etc) passing through a wide variety of topics like wellbore stability, well completions and of course reservoir characterization. For these reasons, the knowledge of these properties is really valuable for people working in the petroleum industry and of course working in reservoir characterization. This study was located in Berea town, Oklahoma, and it was intended to identify the geomechanical and acoustic properties of a sandstone sample. The Berea sandstone elastic properties are characterized using two methods: Quasi static and Dynamic. A detailed explanation of the sample preparation and the testing procedure is provided. Calculation results for both methods showed consistent values for the Young’s modulus being around 3,000,000 psi. The Poisson’s Ratio value is between 0.13 and 0.3. This study was performed in the PoroMechanics Institute (PMI) in the Sarkeys Energy Center at the University of Oklahoma, USA. Monitoring equipment was used to obtain all the information necessary for the proper characterization of the rock. The results of this work are a good tool that can be used in future simulations such as hydraulic fracturing treatment, reservoir fluid flow or reserve estimation.

scholarly journals The Mechanical Properties and Elastic Anisotropies of Cubic Ni3Al from First Principles Calculations

Crystals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 307 ◽  
Author(s):  
Xinghe Luan ◽  
Hongbo Qin ◽  
Fengmei Liu ◽  
Zongbei Dai ◽  
Yaoyong Yi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Modulus ◽  
Bulk Modulus ◽  
Young’S Modulus ◽  
First Principles ◽  
Poisson’S Ratio ◽  
Density Functional ◽  
Young's Modulus ◽  
Small Deviation ◽  
Poisson's Ratio

Ni3Al-based superalloys have excellent mechanical properties which have been widely used in civilian and military fields. In this study, the mechanical properties of the face-centred cubic structure Ni3Al were investigated by a first principles study based on density functional theory (DFT), and the generalized gradient approximation (GGA) was used as the exchange-correlation function. The bulk modulus, Young’s modulus, shear modulus and Poisson’s ratio of Ni3Al polycrystal were calculated by Voigt-Reuss approximation method, which are in good agreement with the existing experimental values. Moreover, directional dependences of bulk modulus, Young’s modulus, shear modulus and Poisson’s ratio of Ni3Al single crystal were explored. In addition, the thermodynamic properties (e.g., Debye temperature) of Ni3Al were investigated based on the calculated elastic constants, indicating an improved accuracy in this study, verified with a small deviation from the previous experimental value.

Effect of Carbon Black on Poisson's Ratio of Elastomers

1975 ◽  
Vol 48 (2) ◽  
pp. 246-253 ◽  
Author(s):  
B. P. Holownia
Keyword(s):  
Carbon Black ◽  
Bulk Modulus ◽  
Experimental Method ◽  
Young’S Modulus ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Poisson's Ratio ◽  
Carbon Black Content ◽  
Practical Applications ◽  
Incompressible Materials

Abstract The experimental method developed is mostly suitable for measuring K of relatively incompressible materials such as members of the elastomer family. The accuracy of K values are estimated to be within ±3% for all rubber specimens. Its use can be extended to plastics with somewhat reduced accuracy. The results show that bulk modulus K for the four different rubbers tested increases almost linearly with carbon black content while the Young's modulus E increases much more rapidly as shown in Figure 3. It is interesting to note that Poisson's ratio v calculated using K and E does not fall below 0.4940 (Figure 5), and the value of v=0.4997 as quoted in engineering handbooks would be reasonable to use for most practical applications where the carbon black content is not excessive.

EFFECT OF PORE FLUIDS ON THE ELASTIC PROPERTIES OF SANDSTONE

Geophysics ◽  
1960 ◽  
Vol 25 (2) ◽  
pp. 433-444 ◽  
Author(s):  
R. L. Mann ◽  
I. Fatt
Keyword(s):  
Young’S Modulus ◽  
Elastic Properties ◽  
Poisson’S Ratio ◽  
Elastic Moduli ◽  
Young's Modulus ◽  
Clay Content ◽  
Poisson's Ratio ◽  
Statistical Validity ◽  
Bulk Compressibility ◽  
Water Saturated

Bulk compressibility, Young’s modulus, and Poisson’s ratio were measured on three sandstones. Measurements were made on both dry and water saturated samples. Several runs were made on each sandstone to establish the statistical validity of the differences observed between the wet and dry samples. Bulk compressibility of wet sandstone was 10 to 30 percent greater than for dry. Young’s modulus was 8 to 20 percent less for wet sandstone, and Poisson’s ratio was 100 percent greater on one type of sandstone when wet and only slightly greater or about the same on wet samples of the others. A high clay content is believed to lead to a large effect of water on the elastic moduli of sandstone.

Elastic moduli of boron nitride, aluminium nitride and gallium nitride nanotubes using second generation reactive empirical bond order potential

2015 ◽  
Vol 11 (1) ◽  
pp. 2-15 ◽  
Author(s):  
Dinesh Kumar ◽  
Veena Verma ◽  
Keya Dharamvir ◽  
H S Bhatti
Keyword(s):  
Shear Modulus ◽  
Young’S Modulus ◽  
Elastic Properties ◽  
Poisson’S Ratio ◽  
Second Generation ◽  
Young's Modulus ◽  
Poisson's Ratio ◽  
Content Type ◽  
Bond Order Potential ◽  
Rebo Potential

Purpose – The purpose of this paper is to study elastic properties of III-V nitride nanotubes (NNTs) using second generation (REBO) potential. Design/methodology/approach – In the present research paper elastic properties of BN, AlN and GaN nanotubes have been investigated, using the second generation REBO potential by Brenner and co-workers, which is a bond order potential earlier used for carbon nanostructures successfully. In the present calculation, the same form of potential is used with adjusted parameters for h-BN, h-AlN and h-GaN. In all these cases the authors have considered graphite like network and strongly polar nature of these atoms so electrostatic forces are expected to play an important role in determining elastic properties of these nanotubes. The authors generate the coordinates of nanotubes of different chirality’s and size. Each and every structure thus generated is allowed to relax till the authors obtain minima of energy. The authors then apply the requisite compressions, elongations and twists to the structures and compute the elastic moduli. Young’s Modulus, Shear Modulus and Poisson’s ratio for single-walled armchair and zigzag tubes of different chirality’s and size have been calculated. The computational results show the variation of Young’s Modulus, Poisson’s ratio and Shear Modulus for these NNTs with nanotube diameter. The results have been compared with available data, experimental as well as theoretical. Findings – The authors have calculated bond length, cohesive energy/bond, Strain energy, Young’s Modulus, Shear Modulus and Poisson’s ratio. Originality/value – To the best of the knowledge this work is the first attempt to study elastic properties of III-V NNTs using second generation REBO potential

scholarly journals Research on Mechanical Properties of High-Pressure Anhydrite Based on First Principles

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 240
Author(s):  
Xianren Zeng ◽  
Shihui You ◽  
Linmei Li ◽  
Zhangli Lai ◽  
Guangyan Hu ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Bulk Modulus ◽  
Young’S Modulus ◽  
First Principles ◽  
Poisson’S Ratio ◽  
Young's Modulus ◽  
Three Dimensional ◽  
Poisson's Ratio ◽  
Physical Parameters ◽  
Three Dimensional Model

This article focuses on the elucidation of a three-dimensional model of the structure of anhydrite crystal (CaSO4). The structure parameters of anhydrite crystal were obtained by means of first principles after structure optimization at 0~120 MPa. In comparison with previous experimental and theoretical calculation values, the results we obtained are strikingly similar to the previous data. The elastic constants and physical parameters of anhydrite crystal were also studied by the first-principles method. Based on this, we further studied the Young’s modulus and Poisson’s ratio of anhydrite crystal, the anisotropy factor, the speed of sound, the minimum thermal conductivity and the hardness of the material. It was shown that the bulk modulus and Poisson’s ratio of anhydrite crystal rose slowly with increasing pressure. The anisotropy characteristics of the Young’s modulus and shear modulus of anhydrite crystal were consistent under various pressure levels, while the difference in the anisotropy characteristics of the bulk modulus appeared. The acoustic velocities of anhydrite crystal tended to be stable with increasing pressure. The minimum thermal conductivity remained relatively unchanged with increasing pressure. However, the material hardness declined gradually with increasing pressure.

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