scholarly journals Using Molecular Dynamics Simulation to Analyze the Feasibility of Using Waste Cooking Oil as an Alternative Rejuvenator for Aged Asphalt

2021 ◽  
Vol 13 (8) ◽  
pp. 4373
Author(s):  
Lin Li ◽  
Cheng Xin ◽  
Mingyang Guan ◽  
Meng Guo
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Elastic Modulus ◽  
Shear Modulus ◽  
Bulk Modulus ◽  
Md Simulation ◽  
Waste Cooking Oil ◽  
Dynamics Simulation ◽  
Cooking Oil ◽  
Aged Asphalt

The purpose of this study was to investigate the regeneration effect of waste cooking oil (WCO) on aged asphalt with molecular dynamics (MD) simulation, comparing it with a rejuvenator. Firstly, the molecular models of virgin and aged asphalt were established by blending the four components of asphalt (saturate, aromatic, resin, and asphaltenes). Then, different dosages of the rejuvenator and WCO (6, 9, and 12%) were included in the aged asphalt model for its regeneration. After that, MD simulations were utilized for researching the mechanical and cohesive properties of the recycled asphalt, including its density, viscosity, cohesive energy density (CED), shear modulus (G), bulk modulus (K), and elastic modulus (E). The results show that the density values of the asphalt models were relatively lower than the existing experimental results in the literature, which is mostly attributed to the fact that the heteroatoms of the asphalt molecules were not considered in the simulation. On the other hand, the WCO addition decreased the viscosity, the shear modulus (G), the bulk modulus (K), and the elastic modulus (E) of the aged asphalt, improving its CED. Moreover, the nature of the aged asphalt was gradually restored with increasing rejuvenator or WCO contents. Compared with the rejuvenator, the viscosity of the aged asphalt was more effectively restored through adding WCO, while the effect of the CED and the mechanical properties recovery of the aged asphalt was relatively low. This implies that WCO could restore partial mechanical properties of aging asphalt, which proves the possibility of using WCO as an asphalt rejuvenator. Additionally, the MD simulation played an important role in understanding the molecular interactions among the four components of asphalt and the rejuvenator, which will serve as a guideline to better design a WCO rejuvenator and optimize its content.

Effects of defects and functional groups on graphene and nanotube thermoset epoxy-based nanocomposites mechanical properties using molecular dynamics simulation

2020 ◽  
pp. 096739112092907 ◽  
Author(s):  
Mahmoud Haghighi ◽  
Ali Khodadadi ◽  
Hossein Golestanian ◽  
Farshid Aghadavoudi
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Elastic Modulus ◽  
Functional Groups ◽  
Md Simulation ◽  
Matrix Material ◽  
Mixed Effects ◽  
Dynamics Simulation ◽  
The Matrix ◽  
Thermoset Epoxy

In this article, several thermoset epoxy-based nanocomposites are simulated using molecular dynamics (MD) simulation. Epoxy resin with 75% crosslinking ratio is modeled first and its properties are used as the matrix material mechanical properties. The effects of defects and functional groups on carbon nanotube- and nanographene-reinforced epoxy nanocomposites are investigated. To achieve our goals, various types of defects and functional groups are created on graphene and nanotube in the MD models. The defects consist of Stone–Wales, vacancy, and Adatom. In addition, functional groups consist of O, OH, COOH, and NH2. Mechanical properties of nanocomposites are determined and compared. Moreover, nanocomposites consisting of continuous and short reinforcements are modeled to investigate the effects of reinforcement length on nanocomposite mechanical properties. Numerical results show that defects and functional groups reduce the elastic modulus of the nanofillers and nanocomposites in continuous nanofiller-reinforced epoxy. However, in nanocomposites consisting of short nanofillers, defects and functional groups have mixed effects on nanocomposite mechanical properties.

Effect of Size on the Mechanical Properties of Rh-20at%Pd Nanowire

2011 ◽  
Vol 403-408 ◽  
pp. 1173-1177
Author(s):  
Jamal Davoodi ◽  
Mohammad Javad Moradi
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Bulk Modulus ◽  
Elastic Constants ◽  
Constant Pressure ◽  
Young Modulus ◽  
Dynamics Simulation ◽  
Many Body ◽  
Temperature Constant ◽  
Body Potential

The aim of this research was to calculate Yong modulus, Bulk modulus and the elastic constants of Rh-20at%Pd (atom percent) nanowire. The molecular dynamics simulation technique was used to calculate the mechanical properties at constant temperature, constant pressure ensemble. The cohesive energy of the model nanowire systems was calculated by Quantum Sutton-Chen many body potential. The temperature and the pressure of the system were controlled by Nose-Hoover thermostat and Berendsen barostat, respectivly. In addition effects of the diameter of nanowire on the mechanical properties were studied. The obtained results show that, when the diameter of Rh-Pd nanowire increase, elastic constants, bulk modulus and Young modulus all increase, and when the diameter reaches about 5.5 nm, the properties began to level off and remain constant.

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 Influence of Irradiation on Mechanical Properties of Nickel

2019 ◽  
Vol 2019 ◽  
pp. 1-6
Author(s):  
Lei Ma ◽  
Changsheng Li ◽  
Xue Shang ◽  
Wangyu Hu
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Plastic Deformation ◽  
Elastic Modulus ◽  
Md Simulation ◽  
High Energy ◽  
Yield Strain ◽  
Irradiation Energy ◽  
Energy Irradiation ◽  
Simulation Results

The influence of irradiation on mechanical properties of nickel is studied using molecular dynamics (MD) simulation. The single crystal nickel is irradiated with the primary knocked-on atom (PKA) energies of 5 keV, 10 keV, 20 keV, and 30 keV at 300 K, and then the tensile test is performed. The simulation results reveal that the yield strain and yield stress of irradiated nickel decrease with the irradiation energy increasing, while the elastic modulus has no obvious change at various irradiation energies. By analyzing the stress-strain curves and the microstructure evolution, it is found that the effect of irradiation accelerates the damage of the internal structure due to the existence of irradiation defects, and high-energy irradiation leads to the instability of the structure in the process of plastic deformation.

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.

scholarly journals Mechanical behaviour of graphdiyne film: experimental and molecular dynamics simulation

2018 ◽  
Vol 183 ◽  
pp. 01011 ◽  
Author(s):  
Kailu Xiao ◽  
Xianqian Wu ◽  
Qiuyun Yin ◽  
Chenguang Huang
Keyword(s):  
Molecular Dynamics ◽  
Elastic Modulus ◽  
Molecular Dynamics Simulation ◽  
Md Simulation ◽  
Indentation Depth ◽  
Maximum Stress ◽  
Dynamics Simulation ◽  
Deformation Mechanisms ◽  
Elastic Behaviour ◽  
Critical Depth

AFM experiments and molecular dynamics simulation of rectangular graphdiyne films are performed in this paper. The force-deflection curves are obtained, and the elastic modulus is calculated as 218.5 GPa and 482.615 GPa, respectively. The simulated maximum stress and pre-tension of graphdiyne film are 33.088 GPa and 0.551 GPa, respectively. It is observed that the graphdiyne film fractured in the central point once the indentation depth over the critical depth. Also, the obviously elastic behaviour has found during the loading-unloading-reloading process. The deformation mechanisms and fractured behaviour of the graphdiyne film are discussed in detail during the loading process. Moreover, the effects of various factors including loading speed and indenter radii of the graphdiyne film by the MD simulation are discussed.

scholarly journals Molecular dynamics simulation of the mechanical properties of multilayer graphene oxide nanosheets

RSC Advances ◽  
2017 ◽  
Vol 7 (87) ◽  
pp. 55005-55011 ◽  
Author(s):  
Xu Zhang ◽  
Shuyan Liu ◽  
Han Liu ◽  
Jinwen Zhang ◽  
Xiaoning Yang
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Graphene Oxide ◽  
Molecular Dynamics Simulation ◽  
Failure Mechanism ◽  
Md Simulation ◽  
Dynamics Simulation ◽  
Multilayer Graphene ◽  
Graphene Oxide Nanosheets ◽  
Non Equilibrium

The mechanical properties and failure mechanism of multilayer GO nanosheets were studied by non-equilibrium MD simulation.

Effects of Vacancy Concentration and Temperature on Mechanical Properties of Single-Crystal γ-TiAl Based on Molecular Dynamics Simulation

2018 ◽  
Vol 37 (2) ◽  
pp. 113-120 ◽  
Author(s):  
Feng Ruicheng ◽  
Cao Hui ◽  
Li Haiyan ◽  
Rui Zhiyuan ◽  
Yan Changfeng
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Elastic Modulus ◽  
Molecular Dynamics Simulation ◽  
Vacancy Concentration ◽  
Dynamics Simulation ◽  
Evolution Process ◽  
Micro Cracks ◽  
Different Temperatures ◽  
External Forces

AbstractMolecular dynamics simulation is used to analyze tensile strength and elastic modulus under different temperatures and vacancy concentrations. The effects of temperature and vacancy concentration on the mechanical properties of γ-TiAl alloy are investigated. The results show that the ultimate stress, ultimate strain and elastic modulus decrease nonlinearly with increasing temperature and vacancy concentration. As the temperature increases, the plastic of material is reinforced. The influence of temperature on strength and elastic modulus is larger than that of vacancy concentration. The evolution process of vacancy could be observed clearly. Furthermore, vacancies with different concentrations develop into voids first as a function of external forces or other factors, micro cracks evolve from those voids, those micro cracks then converge to a macro crack, and fracture will finally occur. The vacancy evolution process cannot be observed clearly owing to the thermal motion of atoms at high temperature. In addition, potential energy is affected by both temperature and vacancy concentration.

scholarly journals Molecular Dynamics Study on Mechanical Properties of Nanopolycrystalline Cu–Sn Alloy

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7782
Author(s):  
Guodong Zhang ◽  
Junsheng Zhao ◽  
Pengfei Wang ◽  
Xiaoyu Li ◽  
Yudong Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Dislocation Density ◽  
Strain Rate ◽  
Dynamics Simulation ◽  
Experimental Characterization ◽  
Tensile Process ◽  
Strength And Ductility

Molecular dynamics simulation is one kinds of important methods to research the nanocrystalline materials which is difficult to be studied through experimental characterization. In order to study the effects of Sn content and strain rate on the mechanical properties of nanopolycrystalline Cu–Sn alloy, the tensile simulation of nanopolycrystalline Cu–Sn alloy was carried out by molecular dynamics in the present study. The results demonstrate that the addition of Sn reduces the ductility of Cu–Sn alloy. However, the elastic modulus and tensile strength of Cu–Sn alloy are improved with increasing the Sn content initially, but they will be reduced when the Sn content exceeds 4% and 8%, respectively. Then, strain rate ranges from 1 × 109 s−1 to 5 × 109 s−1 were applied to the Cu–7Sn alloy, the results show that the strain rate influence elastic modulus of nanopolycrystalline Cu–7Sn alloy weakly, but the tensile strength and ductility enhance obviously with increasing the strain rate. Finally, the microstructure evolution of nanopolycrystalline Cu–Sn alloy during the whole tensile process was studied. It is found that the dislocation density in the Cu–Sn alloy reduces with increasing the Sn content. However, high strain rate leads to stacking faults more easily to generate and high dislocation density in the Cu–7Sn alloy.

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