scholarly journals Phase Stability and Mechanical Properties of Al8Fe4RE via First-Principle Calculations

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 701
Author(s):  
Rongcheng Wang ◽  
Xiaoma Tao ◽  
Hongmei Chen ◽  
Yifang Ouyang
Keyword(s):  
Young’S Modulus ◽  
Phase Stability ◽  
Young's Modulus ◽  
Dynamic Properties ◽  
First Principle ◽  
Lattice Constants ◽  
First Principle Calculations ◽  
Phonon Spectra ◽  
Calculated Enthalpy ◽  
3D Surfaces

We report on the phase stability, elastic, electronic, and lattice dynamic properties of 17 Al8Fe4RE (RE = Sc, Y, La–Lu) intermetallic compounds (IMCs) using first-principle calculations. The calculated lattice constants coincided with the experimental results. The calculated enthalpy formation indicated that all the 17 IMCs are stable. The elastic constants and various moduli indicated that Al8Fe4RE can be used as a strengthening phase due to its high Young’s modulus and shear modulus. The 3D surfaces of Young’s modulus for Al8Fe4RE showed anisotropic behavior, and the values of hardness for the IMCs were high (about 14 GPa). The phonon spectra showed that only Al8Fe4Y had a soft mode, which means the other IMCs are all dynamically stable.

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.

Correlation Analysis between Dynamic Young’s Modulus and Static MOE of the Poplar LVL Reinforced with Multilayer Fiberglass Mesh

2010 ◽  
Vol 26-28 ◽  
pp. 936-939
Author(s):  
Li Zhang ◽  
Ying Cheng Hu
Keyword(s):  
Correlation Analysis ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Dynamic Properties ◽  
Longitudinal Vibration ◽  
Flexural Vibration ◽  
Transmission Method ◽  
Vibration Method ◽  
Dynamic Young’S Modulus ◽  
Dynamic Young's Modulus

In this paper, the poplar LVL was reinforced with multilayer fiberglass mesh. The reinforcing effect of adding position of fiberglass mesh on improving the static MOE was studied. And three different nondestructive testing (NDT) methods, such as the longitudinal transmission method, longitudinal vibration method and flexural vibration method (out-plane and in-plane), were used to test the dynamic properties of the reinforced poplar LVL. The correlation analysis was implemented between the dynamic Young’s modulus and the static MOE of the reinforced poplar LVL. It can be concluded that the three NDT methods are useful for predicting the MOE of reinforced LVL, but the flexural and longitudinal vibration methods had better accuracy to estimate the MOE.

scholarly journals Measurement of the double-differential neutron cross section of UO2 from room temperature to hot full power conditions

2020 ◽  
Vol 239 ◽  
pp. 14003
Author(s):  
Gilles Noguere ◽  
Shuqi Xu ◽  
Alain Filhol ◽  
Jacques Ollivier ◽  
Emmanuel Farhi ◽  
...  
Keyword(s):  
Room Temperature ◽  
Neutron Cross Section ◽  
Scattering Data ◽  
First Principle ◽  
Harmonic Vibrations ◽  
First Principle Calculations ◽  
The North ◽  
Phonon Spectra ◽  
Densities Of States ◽  
Full Power

Experimental phonon densities of states of UO2 have been deduced from double-differential neutron scattering data measured at 300 K, 600 K and 900 K using the IN6 time-of-flight spectrometer of the Institute Laue-langevin (ILL). The comparison with ab intio phonon spectra obtained at the North Caroline South University from first-principle calculations confirms that harmonic vibrations of the atoms cannot accurately reproduce the phonon broadening related to the oxygen atoms.

scholarly journals Inverse Identification Of Elastic Moduli For 3D Printed PLA, Using Impulse Excitation Technique (IET)

2021 ◽  
Author(s):  
Afridi Mohsin
Keyword(s):  
Young’S Modulus ◽  
Young's Modulus ◽  
Bulk Material ◽  
Dynamic Properties ◽  
Test Results ◽  
Young’S Moduli ◽  
Vibration Experiment ◽  
3D Printed ◽  
Printed Materials

3D Printing has recently undergone extensive development due to its lower cost and flexibility. A number of studies have been carried out to determine 3D printed material properties. This study focuses on the determination of the dynamic properties for PLA. The PLA material is processed through the popular FDM method with three different build orientations. A vibration experiment is conducted to evaluate the first modal frequency and Young’s modulus. The results are then compared to the FEM modal analysis and finally the traditional tensile testing results. The anisotropy of the 3D printed components, mainly due to the density changes caused by voids and filament alignment, result in the variation of the Young’s modulus which is different than the homogenous bulk material. The calculated Young’s moduli values are very slightly higher than the tensile test results which is in conformance with the trend documented by earlier studies on similar printed materials using the same techniques

Phase Stability and Mechanical Properties of Metastable Ti-X-Sn-Zr (x=Cr, Nb or Fe) Alloys

2018 ◽  
Vol 941 ◽  
pp. 1228-1231 ◽  
Author(s):  
Yonosuke Murayama ◽  
Hiroto Shioiri
Keyword(s):  
Young’S Modulus ◽  
Phase Stability ◽  
Young's Modulus ◽  
Beta Phase ◽  
Large Elongation ◽  
Recovered Strain ◽  
Fe Alloys ◽  
Metastable Beta ◽  
Zr Alloy ◽  
Zr Alloys

Metastable beta Ti-Cr-Sn-Zr alloys used as biomaterial show low Young’s modulus and super-elasticity according to the phase stability of their beta phase. In this study, we substituted Nb and Fe for Cr in metastable beta Ti-2Cr-6Sn-45Zr alloy and investigated their effect. We investigated how the added amount of Cr, Nb and Fe influences the phase stability and the properties of low Young’s modulus and super-elasticity in Ti-x-Sn-Zr (x=Cr, Nb or Fe) alloys. The Young’s modulus of a Ti-x-Sn-Zr (x=Cr, Nb or Fe) alloy decreases with the addition of Cr, Nb or Fe. However, the Young’s modulus of a Ti-x-Sn-Zr (x=Cr, Nb or Fe) alloy increases with the addition of Cr, Nb or Fe after showing own minimum value respectively. Minimum Young’s modulus of several Ti-x-Sn-Zr (x=Cr, Nb or Fe) alloys were under 50GPa. The required amount of Cr, Nb or Fe in the Ti-x-Sn-Zr (x=Cr, Nb or Fe) alloy having minimum Young’s modulus is different according to the beta stabilizing ability of each element. Fe amounts were the smallest and Nb amounts were the largest. Ti-x-Sn-Zr (x=Cr, Nb or Fe) alloy with minimum Young’s modulus shows a stress-induced martensitic transformation. However, only Ti-Cr-Sn-Zr alloys showed definite super-elasticity. The recovered strain by super-elasticity is small in Ti-Nb-Sn-Zr alloy. Ti-Fe-Sn-Zr alloy didn’t show super-elasticity or large elongation.

Longitudinal vibration wave in the composite elastic metamaterials containing Bragg structure and local resonator

2020 ◽  
Vol 34 (26) ◽  
pp. 2050232
Author(s):  
Xiaofei Lei ◽  
Peng Chen ◽  
Heping Hou ◽  
Shanhui Liu ◽  
Peng Liu
Keyword(s):  
Mathematical Model ◽  
Young’S Modulus ◽  
Transmission Spectrum ◽  
Strain Energy ◽  
Young's Modulus ◽  
Dynamic Properties ◽  
Longitudinal Vibration ◽  
Total Width ◽  
Bragg Structure ◽  
Vibration Wave

In this paper, a novel composite acoustical hyperstructure of Bragg structure with local resonator is investigated theoretically for discussing the scattering performance of longitudinal vibration wave, its bandgaps are calculated using the established mathematical model. For confirming the veritable existence of bandgap and verifying the correctness of established mathematical model, the transmission spectrum of composite acoustical hyperstructure is also studied using finite-element method, and comparing the vibration transmission spectrum with bandgaps, the results indicate that the established theoretical model can correctly predict longitudinal wave bandgaps. Moreover, the bandgaps and modes shapes are calculated and compared with an unalloyed Bragg structure for probing the dispersion mechanics of composite acoustical hyperstructure, it turned out that local resonator can add one bandgap at the base of Bragg structure and the total bandgaps can be broadened. Further, for discussing the effect of spring of local resonator on bandgaps, bandgap of local resonator with different spring is calculated, the results showed that the total width of BG is larger when Young’s modulus is 1E and 16E, the total width are 772.48 and 774.30 Hz, respectively; as Young’s modulus is 0.5E and 2E, the width of BG are lower, 753.79 and 754.23 Hz, respectively. In view of longitudinal vibration wave inducing structural distortion and vibration energy conversion, the dynamic properties of composite acoustical hyperstructure are studied via strain energy density, the results indicate that reaction formation of local resonator can dissipate strain energy, when the local resonator is not activated (or waveless along with Bragg structure), un-dissipation strain energy.

Determination of Young's modulus and shear modulus by means of deflection curves for wood beams obtained in static bending tests

Holzforschung ◽  
2007 ◽  
Vol 61 (5) ◽  
pp. 589-594 ◽  
Author(s):  
Koji Murata ◽  
Tsubasa Kanazawa
Keyword(s):  
Shear Modulus ◽  
Young’S Modulus ◽  
Polynomial Regression ◽  
Young's Modulus ◽  
Dynamic Properties ◽  
Flexural Vibration ◽  
Bending Test ◽  
Deflection Curve ◽  
Element Analysis ◽  
Static Young’S Modulus

Abstract Young's modulus and shear modulus were simultaneously obtained in a three-point bending test based on Timoshenko's bending theory. Deflection curves of a bent beam were measured by image analysis, and the mechanical properties of the wood were calculated by polynomial regression analysis after excluding the singular region. When beam specimens of spruce (Picea sp.) and mizunara (Quercus crispula) wood were tested, static Young's modulus (E s) and static shear modulus (G s) values could be obtained from the deflection curve using finite element analysis. By comparing the dynamic properties (E d and G d) obtained by a flexural vibration test, it was estimated that E s was greater than E d, while G s was less than G d. However, we suppose that the G s values calculated from the deflection curve are more plausible than those obtained from a conventional bending test.

Phase Stability and Mechanical Properties of Ti-Cr Based Alloys with Low Young’s Modulus

2010 ◽  
Vol 654-656 ◽  
pp. 2114-2117 ◽  
Author(s):  
Yonosuke Murayama ◽  
Shuichi Sasaki ◽  
Hisamichi Kimura ◽  
Akihiko Chiba
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Phase Stability ◽  
Deformation Mechanism ◽  
Young's Modulus ◽  
Deformation Behaviour ◽  
System Alloy ◽  
Β Phase ◽  
Ω Phase ◽  
Cr System

This work investigates the mechanical properties of Ti-Cr system alloys and focuses on the microstructure, the Young’s modulus, the deformation mechanism and the deformation behaviour observed in various alloy compositions. The addition of Al to the Ti-Cr system alloys greatly decreases the Young’s modulus. Addition of Al, Sn and Zr to various Ti-Cr alloys suppresses the athermal ω phase that forms during quenching from β field. A Ti-Cr system alloy with low Young’s modulus was obtained in suitable compositional combination of Cr, Zr and Sn or Al. The alloys with the composition where the quenched microstructure transits from martensite to meta-stable β phase show low Young’s modulus. In addition, the alloys show two-step yielding due to stress-induced transformation.

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