scholarly journals Investigation on Cf/PyC Interfacial Properties of C/C Composites by the Molecular Dynamics Simulation Method

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 679
Author(s):  
Yuan Zhou ◽  
Tianyuan Ye ◽  
Long Ma ◽  
Zixing Lu ◽  
Zhenyu Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Md Simulation ◽  
Average Length ◽  
Tensile Load ◽  
Simulation Method ◽  
Dynamics Simulation ◽  
Force Model ◽  
Element Analysis ◽  
Simulation Results

In this paper, a molecular dynamics (MD) simulation model of carbon-fiber/pyrolytic-carbon (Cf/PyC) interphase in carbon/carbon (C/C) composites manufactured by the chemical vapor phase infiltration (CVI) process was established based on microscopic observation results. By using the MD simulation method, the mechanical properties of the Cf/PyC interphase under tangential shear and a normal tensile load were studied, respectively. Meanwhile, the deformation and failure mechanisms of the interphase were investigated with different sizes of the average length L ¯ a of fiber surface sheets. The empirical formula of the interfacial modulus and strength with the change of L ¯ a was obtained as well. The shear properties of the isotropic pyrolysis carbon (IPyC) matrix were also presented by MD simulation. Finally, the mechanical properties obtained by the MD simulation were substituted into the cohesive force model, and a fiber ejection test of the C/C composite was simulated by the finite element analysis (FEA) method. The simulation results were in good agreement with the experimental ones. The MD simulation results show that the shear performance of the Cf/PyC interphase is relatively higher when L ¯ a is small due to the effects of non-in-plane shear, the barrier between crystals, and long sheet folding. On the other hand, the size of L ¯ a has no obvious influence on the interfacial normal tensile mechanical properties.

A Study on Surface Friction on Gold Substrate With 2D Molecular Dynamics Simulation

2008 ◽  
Author(s):  
Hualong Yu ◽  
Q. Jane Wang
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Md Simulation ◽  
Surface Friction ◽  
Gold Surface ◽  
Simulation Method ◽  
Dynamics Simulation ◽  
Two Dimensional ◽  
Gold Substrate ◽  
Simulation Results

This paper reports a study on the contact and friction between a gold surface and a rigid tip with a two-dimensional (2D) classical Molecular Dynamics (MD) simulation method. A multiscale method is used in the MD simulation. The MD simulation results are compared with the Hertzian cylindrical contact results. A criterion for the transition from surface sliding to surface scratching is also discussed with the assistance of stress analyses.

Molecular Dynamics Simulation of Crack Initiation of Aluminum under Tensile Deformation

2011 ◽  
Vol 378-379 ◽  
pp. 7-10
Author(s):  
Gui Xue Bian ◽  
Yue Liang Chen ◽  
Jian Jun Hu ◽  
Li Xu
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Elastic Constants ◽  
Tensile Deformation ◽  
Crack Nucleation ◽  
Tensile Load ◽  
Dynamics Simulation ◽  
Metal Aluminum ◽  
Impurity Metal

Molecular dynamics simulation was used to simulate the tension process of purity and containing impurity metal aluminum. Elastic constants of purity and containing impurity metal aluminum were calculated, and the effects of impurity on the elastic constants were also studied. The results show that O-Al bond and Al-Al bond near oxygen atoms could be the sites of crack nucleation or growth under tensile load, the method can be extended to research mechanical properties of other metals and alloys structures.

Molecular Dynamics Simulations of Nanocomposite Diamond-Like Carbon

2005 ◽  
Author(s):  
G. T. Gao ◽  
J. D. Schall ◽  
K. Van Workum ◽  
P. T. Mikulski ◽  
J. A. Harrison
Keyword(s):  
Molecular Dynamics ◽  
Elastic Constants ◽  
Simulation Method ◽  
Dynamics Simulation ◽  
Diamond Structure ◽  
The Core ◽  
Constant Tension ◽  
Simulation Results ◽  
Dynamics Simulations ◽  
Carbon Network

A constant tension and constant temperature molecular dynamics simulation method was used in the calculations of the elastic constants of the nanocomposite systems. The nanocomposite systems contain a core of sp3 diamond structure surrounded by an amorphous carbon network. The simulation results show that the elastic properties of nanocomposites of diamond-like carbons are closely related to the size of the sp3 diamond core; the bigger the core, the larger the elastic constants, and the system becomes more anisotropic.

Effect of w/c ratio and cement content on diffusivity of chloride ion in concrete: A molecular dynamics study

2019 ◽  
Vol 10 (4) ◽  
pp. 83
Author(s):  
Rokonuzzaman Rokon ◽  
Md. Shafiqul Islam ◽  
Nusrat E. Mursalin
Keyword(s):  
Molecular Dynamics ◽  
Diffusion Coefficient ◽  
Diffusion Coefficients ◽  
Md Simulation ◽  
Cement Content ◽  
Chloride Ion ◽  
Simulation Method ◽  
Chloride Induced Corrosion ◽  
Simulation Results ◽  
And Performance

When a reinforced structure is exposed to marine environments, chloride-induced corrosion occurs and it decreases the durability and performance of the structure. The degree of humidity, the presence of cracks, environmental conditions, w/c ratio, and cement content are the influencing factors for chloride ion ingress into concrete. All of them, w/c ratio and cement content are treated as the most crucial factors on diffusion. This paper focus on Molecular Dynamics (MD) simulation method to determine the diffusion coefficient of chloride ion in concrete. The effect of w/c ratio and cement content on the diffusivity of chloride ion is also evaluated. The diffusion coefficients are obtained 2.88x10-12 m2/s, 3.13x10-12 m2/s, and 3.61x10-12 m2/s respectively for different w/c ratio of 0.40, 0.45 and 0.50 with constant cement content. Again the diffusion coefficient are calculated 4.6x10-12 m2/s, 3.13x10-12 m2/s, 2.78x10-12 m2/s respectively for different cement content of 300 kg/m3, 350 kg/m3 and 400 kg/m3 with constant w/c ratio. The simulation results clearly indicate that the diffusion coefficient of chlorine was affected by w/c ratio and cement content significantly.

STUDY OF AFFINITIES BETWEEN SINGLE-WALLED NANOTUBE AND EPOXY RESIN USING MOLECULAR DYNAMICS SIMULATION

2006 ◽  
Vol 05 (01) ◽  
pp. 131-144 ◽  
Author(s):  
JIHUA GOU ◽  
BIN FAN ◽  
GANGBING SONG ◽  
AURANGZEB KHAN
Keyword(s):  
Molecular Dynamics ◽  
Epoxy Resin ◽  
Md Simulation ◽  
Average Distance ◽  
Md Simulations ◽  
Dynamics Simulation ◽  
Repulsive Interaction ◽  
Curing Agent ◽  
Single Walled Nanotubes ◽  
Simulation Results

In the processing of carbon nanotube/polymer composites, the interactions between the nanotube and polymer matrix will occur at the molecular level. Understanding their interactions before curing is crucial for nanocomposites processing. In this study, molecular dynamics (MD) simulations were employed to reveal molecular interactions between (10, 10) single-walled nanotube and two kinds of epoxy resin systems. The two kinds of resin systems were EPON 862/EPI-CURE W curing agent (DETDA) and DGEBA (diglycidylether of bisphenol A)diethylenetriamine (DETA) curing agent. The MD simulation results show that the EPON 862, DETDA and DGEBA molecules had strong attractive interactions with single-walled nanotubes and their molecules changed their conformation to align their aromatic rings parallel to the nanotube surface due to π-stacking effect, whereas the DETA molecule had a repulsive interaction with the single-walled nanotubes. The interaction energies of the molecular systems were also calculated. Furthermore, an affinity index (AI) of the average distance between the atoms of the resin molecule and nanotube surface was defined to quantify the affinities between the nanotubes and resin molecules. The MD simulation results show that the EPON 862/EPI-CURE W curing agent system has good affinities with single-walled nanotubes.

Mechanical property prediction of starch/polymer composites by molecular dynamics simulation

RSC Advances ◽  
2014 ◽  
Vol 4 (22) ◽  
pp. 11475-11480 ◽  
Author(s):  
Yao-Chun Wang ◽  
Shin-Pon Ju ◽  
Chien-Chia Chen ◽  
Hsin-Tsung Chen ◽  
Jin-Yuan Hsieh
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Polymer Composites ◽  
Md Simulation ◽  
Dynamics Simulation ◽  
Property Prediction ◽  
Mechanical Property Prediction

Molecular dynamics (MD) simulation was used to investigate the mechanical properties of several starch composites.

scholarly journals A molecular dynamics study on the mechanical properties of Fe–Ni alloy nanowires and their temperature dependence

RSC Advances ◽  
2020 ◽  
Vol 10 (66) ◽  
pp. 40084-40091
Author(s):  
Jianxin Chen ◽  
Pengtao Li ◽  
E Emily Lin
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Temperature Dependence ◽  
Deformation Mechanism ◽  
Simulation Method ◽  
Dynamics Simulation ◽  
Ni Alloy ◽  
Alloy Nanowires

Deformation mechanism and mechanical property of Fe–Ni alloy nanowires are investigated through molecular dynamics simulation method.

scholarly journals Estimation of the critical vitrification rate of pure metals using molecular dynamics simulation

2019 ◽  
Vol 486 (2) ◽  
pp. 168-172
Author(s):  
S. A. Rogachev ◽  
A. S. Rogachev ◽  
M. I. Alymov
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Simulation Method ◽  
Dynamics Simulation ◽  
Cooling Rates ◽  
Long Term Stability ◽  
Simulation Results ◽  
Pure Metals ◽  
Range Of Values

A molecular dynamics simulation method was applied for estimation of critical cooling rates (vc) that required for amorphization of pure metals: Mg, Al, Ti, Fe, Co, Ni, Cu, Zr, Mo, Pd, Ag, Ta, W, Pt, Au, and Pb. The range of values vc was found to be from 7.9 × 1011 K/s for Al to 3.8 × 1013 K/s for Zr. The atomic structure obtained at different cooling rates is described. A dependence of the specific volume on temperature was investigated both during the amorphization and crystallization processes. The modelling shows, which metals have the highest temperature range of long-term stability of the amorphous phase (Fe, Mo, Ta, W). Estimates were given for the maximum radius of a melt drop that can be cooled at a rate of vc. The obtained simulation results were compared with available experimental data.

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