The Effects of Thermal Loading on the Mechanical Properties of Interfaces of Dissimilar Materials by Nanoindentation Simulations

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Ningbo Liao ◽  
Ping Yang ◽  
Miao Zhang ◽  
Wei Xue
Keyword(s):  
Heat Transfer ◽  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Thermal Cycling ◽  
Thermal Loading ◽  
Mechanical Test ◽  
Dissimilar Materials ◽  
Md Simulations ◽  
Test Models ◽  
Critical Consideration

Heat transfer across the interfaces of dissimilar materials is a critical consideration in a wide variety of scientific and engineering applications. In this paper, molecular dynamics (MD) simulations are conducted to investigate the effects of thermal loading on mechanical properties of Al–Cu and Cr–Cu interfaces. The mechanical properties are investigated by MD simulations of nanoindentation. Both the results of MD simulations and experiments show the Young’s modulus decrease after thermal cycling, and the Cr–Cu interface is more sensitive to the thermal loading than the Al–Cu interface. The thermal loading and mechanical test models proposed here can be used to evaluate interfacial properties under the effects of heat transferring.

Mechanical Properties of α-Helices Estimated Using Molecular Dynamics and Finite Element Simulations

2008 ◽  
Author(s):  
Peyman Honarmandi ◽  
Philip Bransford ◽  
Roger D. Kamm
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Finite Element ◽  
Solid Mechanics ◽  
Normal Mode Analysis ◽  
Computational Cost ◽  
Md Simulations ◽  
Elastic Stiffness ◽  
Mode Analysis ◽  
Molecular Volume

Mechanical properties of biomolecules and their response to mechanical forces may be studied using Molecular Dynamics (MD) simulations. However, high computational cost is a primary drawback of MD simulations. This paper presents a computational framework based on the integration of the Finite Element Method (FEM) with MD simulations to calculate the mechanical properties of polyalanine α-helix proteins. In this method, proteins are treated as continuum elastic solids with molecular volume defined exclusively by their atomic surface. Therefore, all solid mechanics theories would be applicable for the presumed elastic media. All-atom normal mode analysis is used to calculate protein’s elastic stiffness as input to the FEM. In addition, constant force molecular dynamics (CFMD) simulations can be used to predict other effective mechanical properties, such as the Poisson’s Ratio. Force versus strain data help elucidate the mechanical behavior of α-helices upon application of constant load. The proposed method may be useful in identifying the mechanical properties of any protein or protein assembly with known atomic structure.

Unusually high flexibility of graphene–Cu nanolayered composites under bending

2019 ◽  
Vol 21 (31) ◽  
pp. 17393-17399 ◽  
Author(s):  
Yuxin Zhao ◽  
Xiaoyi Liu ◽  
Jun Zhu ◽  
Sheng-Nian Luo
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Analytical Model ◽  
Md Simulations ◽  
High Flexibility

The mechanical properties of graphene–Cu nanolayered (GCuNL) composites under bend loading are investigated via an energy-based analytical model and molecular dynamics (MD) simulations.

A Study of Nanoparticle-Enhanced Heat Transfer

2010 ◽  
Author(s):  
Lawrence M. Jones ◽  
Timothy Sirk ◽  
Eugene Brown
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Molecular Dynamics ◽  
Heat Flux ◽  
Nuclear Power ◽  
Power Plants ◽  
Md Simulations ◽  
Theoretical Description ◽  
Different Temperatures ◽  
Dynamics Simulations

The study of the heat transfer characteristics of nanofluids, i.e. fluids that are suspensions of nanometer size particles, has gained significant attention in the search for new coolants that can effectively service a variety of needs ranging from the increasing heat transfer demands of ever smaller microelectronic devices to mitigating the effects of loss of coolant accidents in nuclear power plants. Experimental data has shown large increases in thermal conductivity and associated increases in the level of critical heat flux in nuclear reactors; however, in some cases the range of the applicability of the experimental results is uncertain and there is a lack of a theory by which this can be resolved. Complicating the theoretical description of heat transfer in nanofluids is the fact that fluids in the vicinity of the nanoparticles are a complex combination of phase transition, interfacial, and transport phenomena. This paper describes a study in which molecular dynamics simulations were used to enhance the understanding of the effect of nanoparticles on heat transfer. The molecular dynamics (MD) simulations presented here model a Lennard-Jones fluid in a channel where the walls are maintained at different temperatures. The heat flux is calculated for a variety of nanoparticle sizes and concentrations. The results are compared to experimental data in order to provide information that will more confidently bound the data and provide information that will guide the development of more comprehensive theories. We also anticipate that this work could contribute to the design of biosensors where suspended molecules are transported through micro- and nano-channels in the presence of heat transfer.

Temperature Effect on Tensile Behavior of Helical Multi-Shell Gold Nanowires

2006 ◽  
Vol 505-507 ◽  
pp. 385-390 ◽  
Author(s):  
Jenn Sen Lin ◽  
Shin Pon Ju ◽  
Yu-Lin Peng ◽  
Wen Jay Lee
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Tensile Testing ◽  
Constant Strain Rate ◽  
Helical Structure ◽  
Md Simulations ◽  
Tensile Behavior ◽  
Gold Nanowires ◽  
Deformation Behaviors ◽  
Fcc Structure

This study performs molecular dynamics (MD) simulations to investigate the tensile behavior of Helical Multi-Shell (HMS) gold nanowires. As their name suggests, these nanowires have a multi-shell helical structure rather than a conventional bulk FCC structure. The mechanical properties and deformation behaviors of the 7-1, 11-4 and 14-7-1 HMS structures are examined under tensile testing at temperatures between 4K and 300 K and a constant strain rate of 0.003% −1 ps . The results reveal that temperature influences the yielding stress, the Young’s modulus, and the deformation behaviors of HMS nanowires. The yielding stress of the 7-1 structure is found to be higher than that of the 11-4 or 14-7-1 structures. Finally, under different temperature conditions, many different close-packed structures are identified in the nanowires before they fracture.

Simulation of Heat Transfer in Nanoscale Flow Using Molecular Dynamics

2010 ◽  
Author(s):  
Masoud Darbandi ◽  
Hossein Reza Abbasi ◽  
Moslem Sabouri ◽  
Rasool Khaledi-Alidusti
Keyword(s):  
Heat Transfer ◽  
Molecular Dynamics ◽  
Poiseuille Flow ◽  
Velocity Slip ◽  
Md Simulations ◽  
Velocity Profiles ◽  
Dynamics Simulation ◽  
Parallel Plates ◽  
Cross Sectional ◽  
Temperature Distributions

We investigate heat transfer between parallel plates separated by liquid argon using two-dimensional molecular dynamics (MD) simulations incorporating with 6–12 Lennard-Jones potential between molecule pairs. In molecular dynamics simulation of nanoscale flows through nanochannels, it is customary to fix the wall molecules. However, this approach cannot suitably model the heat transfer between the fluid molecules and wall molecules. Alternatively, we use thermal walls constructed from the oscillating molecules, which are connected to their original positions using linear spring forces. This approach is much more effective than the one which uses a fixed lattice wall modeling to simulate the heat transfer between wall and fluid. We implement this idea in analyzing the heat transfer in a few cases, including the shear driven and poiseuille flow with specified heat flux boundary conditions. In this method, the work done by the viscous stress (in case of shear driven flow) and the force applied to the fluid molecules (in case of poiseuille flow) produce heat in the fluid, which is dissipated from the nanochannel walls. We present the velocity profiles and temperature distributions for the both chosen test cases. As a result of interaction between the fluid molecules and their adjacent wall molecules, we can clearly observe the velocity slip in the velocity profiles and the temperature jump in the cross-sectional temperature distributions.

scholarly journals Study on Lightweight and Strengthening Effect of Carbon Nanotube in Highly Ordered Nanoporous Nickel: A Molecular Dynamics Study

2019 ◽  
Vol 9 (2) ◽  
pp. 352 ◽  
Author(s):  
Yu Zhou ◽  
Wu-Gui Jiang ◽  
Duo-Sheng Li ◽  
Qing-Hua Qin
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Carbon Nanotube ◽  
Tensile Modulus ◽  
Md Simulations ◽  
Absorption Capacity ◽  
Atomic Scale ◽  
Strengthening Effect ◽  
Pore Collapse ◽  
Out Of Plane

The mechanical behavior of nanocomposites consisting of highly ordered nanoporous nickel (HONN) and its carbon nanotube (CNT)-reinforced composites (CNHONNs) subjected to a high temperature of 900 K is investigated via molecular dynamics (MD) simulations. The study indicates that, out-of-plane mechanical properties of the HONNs are generally superior to its in-plane mechanical properties. Whereas the CNT shows a significant strengthening effect on the out-of-plane mechanical properties of the CNHONN composites. Compared to pure HONNs, through the addition of CNTs from 1.28 wt‰ to 5.22 wt‰, the weight of the composite can be reduced by 5.83‰ to 2.33% while the tensile modulus, tensile strength, compressive modulus and compressive strength can be increased by 2.2% to 8.8%, 1% to 5.1%, 3.6% to 10.2% and 4.9% to 10.7%, respectively. The energy absorption capacity can also be improved due to the existence of CNTs. Furthermore, the MD simulations provide further insights into the deformation mechanism at the atomic scale, including fracture in tension, pore collapse in compression and local changes in lattice structures due to stacking faults.

Investigation of the mechanical properties and local structural evolution of Ti60Zr10Ta15Si15 bulk metallic glass during tensile deformation: a molecular dynamics study

RSC Advances ◽  
2015 ◽  
Vol 5 (68) ◽  
pp. 55383-55395 ◽  
Author(s):  
Hui-Lung Chen ◽  
Shin-Pon Ju ◽  
Tsang-Yu Wu ◽  
Shih-Hao Liu ◽  
Hsin-Tsung Chen
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Metallic Glass ◽  
Uniaxial Tension ◽  
Bulk Metallic Glass ◽  
Deformation Mechanism ◽  
Tensile Deformation ◽  
Structural Evolution ◽  
Md Simulations ◽  
Local Deformation

The investigations on the structural properties and local deformation mechanism of Ti60Zr10Ta15Si15 bulk metallic glass (BMG) have been conducted by using molecular dynamics (MD) simulations for the uniaxial tension process.

Structure, Mechanical Properties, and Dynamic Fracture in Nanophase Silicon Nitride via Parallel Molecular Dynamics

1996 ◽  
Vol 457 ◽  
Author(s):  
Kenji Tsuruta ◽  
Andrey Omeltchenko ◽  
Aiichiro Nakano ◽  
Rajiv K. Kalia ◽  
Priya Vashishta
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Grain Size ◽  
Silicon Nitride ◽  
Dynamic Fracture ◽  
Elastic Moduli ◽  
Md Simulations ◽  
Multiphase Model ◽  
Order Of Magnitude ◽  
Parallel Molecular Dynamics

ABSTRACTMillion-atom molecular-dynamics (MD) simulations are performed to study the structure, mechanical properties, and dynamic fracture in nanophase Si3N4. We find that intercluster regions are highly disordered: 50% of Si atoms in intercluster regions are three-fold coordinated. Elastic moduli of nanophase Si3N4 as a function of grain size and porosity are well described by a multiphase model for heterogeneous materials. The study of fracture in the nanophase Si3N4 reveals that the system can sustain an order-of-magnitude larger external load than crystalline Si3N4. This is due to branching and pinning of the crack front by nanoscale microstructures.

Investigating the Effect of Stone-Wales Defect on Young Modulus of Armchair Single Wall Carbon Nanotube Using Molecular Dynamics Simulation

2010 ◽  
Author(s):  
H. Rezaei Nejad ◽  
M. Ghasemi ◽  
A. Shahabi ◽  
S. M. Mirnouri Langroudi
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Young Modulus ◽  
Effective Elastic Modulus ◽  
Md Simulations ◽  
Dynamics Simulation ◽  
Fortran Code ◽  
Wales Defect

Effect of Stone-Wales percentage defect on effective elastic modulus of single-walled carbon nanotubes (SWCNT) is investigated. The Stone-Wales defect is a crystallographic defect that happens in nanotubes and is believed to affect the nanotubes mechanical properties. In order to calculate the mechanical properties of SWCNTs under axial tension, molecular dynamics (MD) simulations using the Morse potential is performed. An in house FORTRAN code is developed and utilized. The Young’s modulus of the perfect SWCNTs and those with different defect percentage is obtained using the classical elasticity theory. It is observed that for low percentage of defect (less than 8%) as the diameter increases the Young’s modulus of SWCNTs slightly increases. However, for high percentage of defect (more than 8%) as diameter increases the Young modulus clearly decreases.

Molecular dynamics simulations on the effects of carbon nanotubes on mechanical properties of bisphenol E cyanate ester validating experimental results

2016 ◽  
Vol 36 (3) ◽  
pp. 186-195 ◽  
Author(s):  
P Subba Rao ◽  
K Renji ◽  
MR Bhat
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Molecular Dynamics ◽  
Experimental Studies ◽  
Md Simulations ◽  
Geometric Optimization ◽  
Cyanate Ester ◽  
Computational Method ◽  
Interfacial Region ◽  
Atomistic Models

This paper presents molecular dynamics (MD) simulations on the effects of carbon nanotubes (CNTs) without and with chemical functionalization, on the mechanical properties of bisphenol E cyanate ester (BECy) – a potential structural resin. Atomistic models of CNTs, functionalized CNTs (fCNTs), BECy resin, CNT-BECy and fCNT-BECy resins with definite quantity of CNT/fCNT are built. Using these atomistic models, mechanical properties of the above nanosystems are estimated through a computational method involving geometric optimization and equilibration through MD by judiciously establishing various parameters. Adoptability of the approach taken up in this work to model and solve complex nanosystems capturing interactions in the interfacial region between CNT/fCNT and the resin to understand the mechanical behaviour has been highlighted. These investigations have yielded interesting and encouraging results to arrive at optimum quantity of CNTs/fCNTs to be added to achieve enhanced mechanical properties of BECy resin that validate the previous experimental studies carried out by the authors infusing similar quantities of CNTs and fCNTs into BECy.

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