ATOMISTIC SIMULATION OF THE MECHANICAL BEHAVIOR OF Ni3Al NANOWIRES

2010 ◽  
Vol 24 (15) ◽  
pp. 1639-1645 ◽  
Author(s):  
DENGMU CHENG ◽  
SHENGJIE WANG ◽  
CHUNDONG WANG ◽  
ZHIGUO WANG
Keyword(s):  
Atomistic Simulation ◽  
Tensile Strain ◽  
Room Temperature ◽  
Elastic Limit ◽  
Uniform Elongation ◽  
Compressive Strain ◽  
Applied Strain ◽  
Simulation Results ◽  
Mechanism Of Failure ◽  
Elastic Stage

Simulations have been carried out on [001]-oriented Ni 3 Al nanowires with square cross-section with the purpose to investigate the mechanism of failure under tensile and compressive strain. Simulation results show that the elastic limit of the nanowire is up to about 15% strain with the yield stress of 5.99–6.48 GPa under tensile strain. Under the elastic stage, the deformation is carried mainly through the uniform elongation of the bonds between atoms. With more tensile strain, the slips in the {111} planes occur to accommodate the applied strain at room temperature under tensile strain. And the nanowires accommodate the compressive strain by forming the twins within the nanowires.

scholarly journals Simulation Study of Helium Effect on the Microstructure of Nanocrystalline Body-Centered Cubic Iron

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 91 ◽  
Author(s):  
Chunping Xu ◽  
Wenjun Wang
Keyword(s):  
Lattice Constant ◽  
Tensile Strain ◽  
Room Temperature ◽  
Md Simulation ◽  
Uniaxial Tensile ◽  
Body Centered Cubic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Swelling Rate ◽  
Simulation Results

Helium (He) effect on the microstructure of nanocrystalline body-centered cubic iron (BCC-Fe) was studied through Molecular Dynamics (MD) simulation and simulated X-ray Diffraction (XRD). The crack generation and the change of lattice constant were investigated under a uniaxial tensile strain at room temperature to explore the roles of He concentration and distribution played in the degradation of mechanical properties. The simulation results show that the expansion of the lattice constant decreases and the swelling rate increases while the He in the BCC region diffuses into the grain boundary (GB) region. The mechanical property of nanocrystalline BCC-Fe shows He concentration and distribution dependence, and the existence of He in GB is found to benefit the generation and growth of cracks and to affect the strength of GB during loading. It is observed that the reduction of tensile stress contributed by GB He is more obvious than that contributed by grain interior He.

Remote Strain Measurement by Multi-Walled Carbon Nanotube-Dispersed Resin

2009 ◽  
Author(s):  
Katsuya Osaki ◽  
Hideki Fuji ◽  
Masato Onishi ◽  
Ken Suzuki ◽  
Hideo Miura
Keyword(s):  
Strain Measurement ◽  
Tensile Strain ◽  
Axial Strain ◽  
Compressive Strain ◽  
Electronic Conductivity ◽  
Applied Strain ◽  
Dynamic Strain ◽  
Electric Resistance ◽  
Resistance Change ◽  
Base Materials

A new remote strain measurement method has been developed by applying the highly sensitive change of electronic conductivity of CNTs. Multi-walled CNTs were dispersed in various kinds of resins to form a thin film which can be attached rounded surfaces. The length of the CNTs was about a few μm. One of the base materials of resin employed was polycarbonate and the volumetric concentration of CNT dispersed was about 11.5%. The thickness of the film was about 500 μm. An uni-axial strain was applied to the CNT-dispersed resin by applying a 4 point bending method, and the change of the electric resistance was measured. The range of the applied strain was from −0.025% to 0.025%. The electric resistance changed almost linearly with the applied strain. The ratio of the resistance change under the tensile strain was about 40%/1000-μstrain and that under the compressive strain was about 15%/1000-μstrain. The micro wave of 99.5 GHz was irradiated to the CNT-dispersed polycarbonate film through the metallic prove 1 mm in diameter. The change of the intensity of the beam reflected from the film was measured by changing the amplitude of the uni-axial in-plane strain applied to the film. The intensity of the reflected beam increased almost linearly with the increase of the applied tensile strain and the change rate of the intensity was about 0.5%/1000-μstrain. This result clearly indicated that the surface dynamic strain can be detected by micro wave nondestructively and remotely.

scholarly journals Morphology and Kinetics Evolution of Nanoscale Phase in Fe–Cr Alloys under External Strain

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 294 ◽  
Author(s):  
Lihui Zhu ◽  
Yongsheng Li ◽  
Shujing Shi ◽  
Zhengwei Yan ◽  
Jing Chen ◽  
...  
Keyword(s):  
Phase Separation ◽  
Tensile Strain ◽  
Compressive Strain ◽  
Three Dimensional ◽  
Particle Number Density ◽  
Phase Region ◽  
Applied Strain ◽  
Uniaxial Tensile ◽  
Α Phase ◽  
Kinetics Of

Uniaxial strain was applied to aging Fe–Cr alloys to study the morphological orientation and kinetics of the nanoscale α′ phase by utilizing phase-field simulation. The effects of applied uniaxial compressive and tensile strain on the two and three-dimensional morphology as well as on the separation kinetics of the α′ phase are quantitatively clarified. Compared with the applied uniaxial tensile strain, the applied uniaxial compressive strain shows a greater effect on the rate of phase separation, lath shape morphology and an increased rate of growth and coarsening in the α′ phase, the boundary of the α + α′ phase region is widened influenced by the applied compressive strain, while the applied tensile strain results in an increase of particle number density and a decrease of particle radius. The peak value of particle size distribution of the α′ phase increases with aging time, while an opposite trend is shown under the applied strain, and there is an obvious deviation from the theoretical distribution of Lifshitz–Slyozov–Wagner under compressive strain. The orientation morphology and kinetic change show the substantial effects of applied strain on the phase separation and supplies the method for the morphological control of nanoscale particles.

Simulation Study on Shear Crack of Steel Plate

2018 ◽  
Vol 941 ◽  
pp. 480-485 ◽  
Author(s):  
Suo Quan Zhang ◽  
Si Hai Jiao ◽  
Jian Hua Ding ◽  
Qing Feng Zhang ◽  
Hong Sheng Jiang
Keyword(s):  
Mechanical Properties ◽  
Deformation Behavior ◽  
Room Temperature ◽  
Steel Plate ◽  
Shear Crack ◽  
Uniform Elongation ◽  
Shear Cracks ◽  
Factors Affecting ◽  
Simulation Results ◽  
Abaqus Software

Abaqus software is used to simulate the deformation behavior of typical steel materials during the shearing process, and to analyze the displacement change of the materials during the shearing process, and to study the main causes of the steel plate shear cracks. The results show that the mechanical properties of the steel, especially the uniform elongation of the steel plate, are important factors affecting the shear crack. At the same time, the room temperature tensile curves of several typical steels are measured. The corresponding relationship between the curve characteristics and the shear cracks is in agreement with the simulation results. Keywords: shear crack, simulation, mechanical properties, uniform elongation

Influence of the substrate on the anomalous Nernst effect of magnetite thin films

2014 ◽  
Vol 1674 ◽  
Author(s):  
R. Ramos ◽  
A. Anadón ◽  
I. Lucas ◽  
L. Farrell ◽  
M.H. Aguirre ◽  
...  
Keyword(s):  
Thin Films ◽  
Comparative Study ◽  
Tensile Strain ◽  
Room Temperature ◽  
Compressive Strain ◽  
Structural Defects ◽  
Nernst Effect ◽  
Phase Boundaries ◽  
Preliminary Results ◽  
Anomalous Nernst Effect

ABSTRACTWe present a comparative study of the anomalous Nernst effect (ANE), measured at room temperature for magnetite thin films deposited on different substrates in order to study the effects induced by the substrate, compressive or tensile strain and structural defects as anti-phase boundaries (APB), on the observed ANE. From our preliminary results we have observed an increase of the measured ANE in the case of compressive strain compared with the tensile one. Moreover our results also suggest that the density of APBs also play an important role in the ANE values.

Compressive and Tensile Strain Capacities of 48” X80 Line Pipes

2012 ◽  
Author(s):  
Hisakazu Tajika ◽  
Satoshi Igi ◽  
Takahiro Sakimoto ◽  
Shigeru Endo ◽  
Seishi Tsuyama ◽  
...  
Keyword(s):  
Tensile Strain ◽  
High Strain ◽  
Uniform Elongation ◽  
Compressive Strain ◽  
Experimental Studies ◽  
Local Buckling ◽  
Base Material ◽  
Pipe Surface ◽  
Strain Capacity ◽  
Strain Limit

This paper presents the results of experimental studies focused on the strain capacity of X80 linepipe. A full-scale bending tests of X80 grade, 48″ high-strain linepipes pressurized to 60% SMYS were conducted to investigate the compressive strain limit and tensile strain limit. The tensile properties Y/T ratios and uniform elongation of the pipes had variety. Three of four pipes are high strain pipes and these Y/T ratios are intentionally low with manufacturing method. One of these high-strain pipe was girth welded in its longitudinal center to investigate the effect of girth weld to strain capacity. The other was set as a conventional pipe that have higher Y/T ratio to make comparative study. The compressive strain limit focused on the critical strain at the formation of local buckling on the compression side of bending. After pipe reaches its endurable maximum moment, one large developed wrinkle and some small wrinkles on the pipe surface during bending deformation were captured relatively well from observation and strain distribution measurement. The tensile strain limit is discussed from the viewpoint of competition of two fracture phenomena: ductile crack initiation/propagation from an artificial notch at the HAZ of the girth weld, and strain concentration and rupture in the base material at the tension (opposite) side of the local buckling position.

Required Linepipe Properties for High Strain Applications and Possible Resolution by Pipe Manufacturing Technology

2008 ◽  
Author(s):  
Hitoshi Asahi ◽  
Eiji Tsuru
Keyword(s):  
Tensile Strain ◽  
Compressive Strain ◽  
Bending Moment ◽  
Uniaxial Tensile ◽  
Buckling Behavior ◽  
Strain Limit ◽  
Bent Pipe ◽  
Uniaxial Tensile Stress ◽  
The Relationship ◽  
Pipe Manufacturing

Application of strain based design to pipelines in arctic or seismic areas has recently been recognized as important. So far, there has been much study performed on tensile strain limit and compressive strain limit. However, the relationship between bending buckling (compressive strain limit) and tensile strain limit has not been discussed. A model using actual stress strain curves suggests that the tensile strain limit increases as Y/T rises under uniaxial tensile stress because a pipe manufacturer usually raises TS instead of lowering YS to achieve low Y/T. Under bending of a pipe with a high D/t, an increase in compressive strain on intrados of a bent pipe at the maximum bending moment (ε-cp*) improves the tensile strain limit because the tensile strain limit is controlled by the onset of buckling or ε-cp* which is increased by lowering Y/T. On the other hand, under bending of a pipe with a low D/t, the tensile strain limit may not be influenced by improvement of buckling behavior because tensile strain on the extrados is already larger than the tensile limit at ε-cp*. Finally, we argue that the balance of major linepipe properties is important. Efforts other than the strict demands for pipe properties are also very important and inevitable to improve the strain capacity of a pipeline.

Compressive strain versus tensile strain

2001 ◽  
Vol 177 (4) ◽  
pp. 238-242 ◽  
Author(s):  
C. Goyhenex ◽  
H. Bulou ◽  
J.P. Deville ◽  
G. Tréglia
Keyword(s):  
Tensile Strain ◽  
Compressive Strain

scholarly journals Enhanced photoresponse of a high-performance self-powered UV photodetector based on ZnO nanorods and a novel electrolyte by the piezo-phototronic effect

RSC Advances ◽  
2018 ◽  
Vol 8 (58) ◽  
pp. 33174-33179 ◽  
Author(s):  
Xiaoli Peng ◽  
Weihao Wang ◽  
Yiyu Zeng ◽  
Xinhua Pan ◽  
Zhizhen Ye ◽  
...  
Keyword(s):  
High Performance ◽  
Tensile Strain ◽  
Compressive Strain ◽  
Zno Nanorods ◽  
Uv Detector ◽  
Uv Photodetector ◽  
Self Powered

A flexible UV detector exhibits high performance. The photoresponse of the device under different upward angles (tensile strain) and downward angles (compressive strain) were studied. A 163% change in responsivity was obtained when the downward angle reached 60°.

Suppressed Distortion Performance Metrics of 20nm GAA-GaN/Al2O3 Nanowire MOSFET: Based on Quantum Numerical Simulation 

2021 ◽  
Author(s):  
Neha Gupta ◽  
Aditya Jain ◽  
Ajay Kumar
Keyword(s):  
High Performance ◽  
Room Temperature ◽  
Performance Metrics ◽  
Crossover Point ◽  
Promising Candidate ◽  
Higher Derivatives ◽  
Low Distortion ◽  
Simulation Results ◽  
Intercept Point ◽  
Nanowire Mosfet

Abstract This work investigates the suppressed distortion performance metrics of gate all around (GAA) Gallium Nitride (GaN)/Al2O3 Nanowire (NW) n-channel MOSFET (GaNNW/Al2O3 MOSFET) based on quantum numerical simulations at room temperature (300 K). The simulation results show high switching ratio (≈109) with low subthreshold swing (67mV/decade), high QF value (4.1mS-decade/mV) of GaNNW/Al2O3-MOSFET in comparison to GaNNW/SiO2 and SiNW MOSFET for Vds=0.4V due to the lower permittivity of GaN and more effective mass of the electron. Furthermore, linearity and distortion performance is also examined by numerically calculating transconductance and its higher derivatives (gm2 and gm3); voltage and current intercept point (VIP2, VIP3 and IIP3); 1-dB compression point; Harmonics distortions (HD2 and HD3) and IMD3. All these parameters show high linearity and low distortion at zero crossover point (where gm3=0) in GaNNW/Al2O3 MOSFET. Thus, GaNNW MOSFET can be considered as a promising candidate for low power high-performance applications. In addition, effect of ambient temperature (250K-450K) on the performance of GaNNW/Al2O3 is studied and discussed in terms of the above mentioned metrics. It is very well exhibited that SS, Ion, Vth, and QF improved when the temperature is lowered which makes it suitable for low-temperature environments. But, linearity degrades as the temperature lowers down.

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