scholarly journals Pressure Dependence of Structural and Mechanical Properties of Single-Crystal Tungsten: A Molecular Dynamics Study

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1898
Author(s):  
Xuepeng Liu ◽  
Kezhong Xu ◽  
Hua Zhai
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
High Pressure ◽  
Single Crystal ◽  
Pressure Dependence ◽  
High Pressures ◽  
External Pressure ◽  
Uniaxial Tensile ◽  
Linear Lattice ◽  
Lattice Contraction

In the current study, molecular dynamics (MD) simulations were performed to study the pressure dependence of the structural and mechanical properties of single-crystal tungsten. The results show that single-crystal tungsten possesses noteworthy high-pressure stability and exhibits linear lattice contraction with increasing external pressure. Consistent with the results of the performed experiments, the predicted elastic moduli, including Young’s modulus, shear modulus, and bulk modulus, as well as Poisson’s ratio and Pugh’s modulus ratio, show a clear increasing trend with the increase in pressure. Under uniaxial tensile loading, the single-crystal tungsten at high pressures experiences a phase transition from BCC to FCC and other disordered structures, which results in a stripe-like morphology in the tungsten crystal. These results are expected to deepen our understanding of the high-pressure structural and mechanical behaviors of tungsten materials.

Monoclinic FeO at high pressures

2008 ◽  
Vol 223 (7/2008) ◽  
Author(s):  
Innokenty Kantor ◽  
Alexander Kurnosov ◽  
Catherine McCammon ◽  
Leonid Dubrovinsky
Keyword(s):  
High Pressure ◽  
Iron Oxide ◽  
Single Crystal ◽  
Diffraction Study ◽  
High Pressures ◽  
X Ray Diffraction ◽  
X Ray

AbstractA high-pressure quasi-single crystal X-ray diffraction study of a synthetic iron oxide Fe

Vacancy and Temperature Effects on Mechanical Properties of Single-Crystal Bulk Mg2Si: A Molecular Dynamics Study

2013 ◽  
Vol 43 (6) ◽  
pp. 1668-1673 ◽  
Author(s):  
Rui Yu ◽  
Shuyong Yang ◽  
Gang Chen ◽  
Pengcheng Zhai ◽  
Lisheng Liu
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Single Crystal ◽  
Temperature Effects ◽  
Crystal Bulk

scholarly journals Molecular Dynamics Simulation Study of the Mechanical Properties of Nanocrystalline Body-Centered Cubic Iron

Surfaces ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 381-391
Author(s):  
Jan Herman ◽  
Marko Govednik ◽  
Sandeep P. Patil ◽  
Bernd Markert
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Strain Rate ◽  
Tensile Tests ◽  
Dynamics Simulation ◽  
Uniaxial Tensile ◽  
Body Centered Cubic ◽  
Bcc Iron ◽  
Average Grain Size ◽  
Study Results

In the present work, the mechanical properties of nanocrystalline body-centered cubic (BCC) iron with an average grain size of 10 Å were investigated using molecular dynamics (MD) simulations. The structure has one layer of crystal grains, which means such a model could represent a structure with directional crystallization. A series of uniaxial tensile tests with different strain rates and temperatures was performed until the full rupture of the model. Moreover, tensile tests of the models with a void at the center and shear tests were carried out. In the tensile test simulations, peak stress and average values of flow stress increase with strain rate. However, the strain rate does not affect the elasticity modulus. Due to the presence of void, stress concentrations in structure have been observed, which leads to dislocation pile-up and grain boundary slips at lower strains. Furthermore, the model with the void reaches lower values of peak stresses as well as stress overshoot compared to the no void model. The study results provide a better understanding of the mechanical response of nanocrystalline BCC iron under various loadings.

scholarly journals Molecular Dynamics Modeling of Mechanical Properties of Polymer Nanocomposites Reinforced by C7N6 Nanosheet

Surfaces ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 240-254
Author(s):  
Qinghua Zhang ◽  
Bohayra Mortazavi ◽  
Fadi Aldakheel
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Thermal Effects ◽  
Carbon Nitride ◽  
Maximum Strength ◽  
Uniaxial Tensile ◽  
Dynamics Modeling ◽  
Cohesive Model ◽  
Molecular Dynamics Modeling ◽  
Carbon Nitride Nanosheets

Carbon-nitride nanosheets have attracted remarkable attention in recent years due to their outstanding physical properties. C7N6 is one of the hotspot nanosheets which possesses excellent mechanical, electrical, and optical properties. In this study, the coupled thermo-mechanical properties of the single nanosheet C7N6 are systematically investigated. Although temperature effects have a strong influence on the mechanical properties of C7N6 monolayer, thermal effects were not fully analyzed for carbon-nitride nanosheet and still an open topic. To this end, the presented contribution aims to highlight this important aspect and investigate the temperature influence on the mechanical stress-strain response. By using molecular dynamics (MD) simulation, we have found out that the C7N6 monolayer’s maximum strength decreases as the temperature increase from 300 K to 1100 K. In the current contribution, 5% to 15% volume fractions of C7N6/P3HT composite were employed to investigate the C7N6 reinforcing ability. Significantly, the uniaxial tensile of C7N6/P3HT composite reveals that 10%C7N6 can enhance the maximum strength of the composite to 121.80 MPa which is 23.51% higher than the pure P3HT matrix. Moreover, to better understand the enhanced mechanism, we proposed a cohesive model to investigate the interface strength between the C7N6 nanosheet and P3HT matrix. This systematic study provides not only a sufficient method to understand the C7N6 thermo-mechanical properties, but also the reinforce mechanism of the C7N6 reinforced nanocomposite. Thus, this work provides a valuable method for the later investigation of the C7N6 nanosheet.

Quasicontinuum Simulation of Uniaxial Tension of Single Crystal Copper Nanowire

2011 ◽  
Vol 694 ◽  
pp. 200-204
Author(s):  
Xing Lei Hu ◽  
Ying Chun Liang ◽  
Jia Xuan Chen ◽  
Hong Min Pen
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Molecular Dynamics ◽  
Finite Element ◽  
Single Crystal ◽  
Size Effects ◽  
Tension Test ◽  
Quasicontinuum Method ◽  
Single Crystal Copper ◽  
Copper Nanowire

Quasicontinuum simulations of tension test of single crystal copper nanowire are performed to analyze deformation mechanism of tension process and size effects of mechanical properties. New tension models of nanowire are constructed by using quasicontinuum method, which has combined molecular dynamics and finite element method. Tension processes of three different length nanowires without notches and those with notches are simulated. Yield strength and elastic modulus are calculated according to the obtained load-displacement curves. Finally, the results show that the mechanical properties of copper nanowire have obvious size effect and the notches have obvious influence on the mechanical properties.

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