Investigation of Coarse-Grained Mesoscale Molecular Models for Mechanical Properties Simulation, as Parameterized Through Molecular Modeling

Hydrocarbon gels contain a number of materials, such as rubber, greases, saponified mineral oils, etc., of great interest for various engineering purposes. Specific requirements in mechanical properties have been met by producing gels in appropriately chosen patterns of constituent components of visible, colloidal, molecular and atomic sizes, ranging from coarse-grained aggregates, represented by sponges, foams, emulsions, etc.; to fine-grained and apparently homogeneous ones, represented by optically clear compounds. The engineer who has to deal with the whole range of such materials will adopt a macroscopic point of view, based on an apparent continuity of all the material structures and of the distributions in space and time of the displacements and forces occurring under mechanical actions. It has been possible to determine these distributions in the framework of a comprehensive scheme in which the fundamental principles of the mechanics of continuous media provide the theoretical basis, and a testing instrument of new design, termed Rheogoniometer, the means of experimental measurement (Weissenberg 1931, 1934, 1946, 1947, 1948).

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New Approach In The Properties Evaluation Of Ultrafine-Grained OFHC Copper

Archives of Metallurgy and Materials ◽

10.1515/amm-2015-0180 ◽

2015 ◽

Vol 60 (2) ◽

pp. 605-614 ◽

Cited By ~ 2

Author(s):

T. Kvačkaj ◽

A. Kováčová ◽

J. Bidulská ◽

R. Bidulský ◽

R. Kočičko

Keyword(s):

Mechanical Properties ◽

Strain Rate ◽

Tensile Tests ◽

Coarse Grained ◽

Wear Behaviour ◽

Ofhc Copper ◽

Strain Rates ◽

Ultrafine Grained ◽

Reduction Of Area ◽

Pin On Disk

AbstractIn this study, static, dynamic and tribological properties of ultrafine-grained (UFG) oxygen-free high thermal conductivity (OFHC) copper were investigated in detail. In order to evaluate the mechanical behaviour at different strain rates, OFHC copper was tested using two devices resulting in static and dynamic regimes. Moreover, the copper was subjected to two different processing methods, which made possible to study the influence of structure. The study of strain rate and microstructure was focused on progress in the mechanical properties after tensile tests. It was found that the strain rate is an important parameter affecting mechanical properties of copper. The ultimate tensile strength increased with the strain rate increasing and this effect was more visible at high strain rates$({\dot \varepsilon} \sim 10^2 \;{\rm{s}}^{ - 1} )$. However, the reduction of area had a different progress depending on microstructural features of materials (coarse-grained vs. ultrafine-grained structure) and introduced strain rate conditions during plastic deformation (static vs. dynamic regime). The wear behaviour of copper was investigated through pin-on-disk tests. The wear tracks examination showed that the delamination and the mild oxidational wears are the main wear mechanisms.

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Evaluation of coarse-grained mechanical properties using small direct shear test

International Journal of Geotechnical Engineering ◽

10.1080/19386362.2018.1505310 ◽

2018 ◽

pp. 1-13 ◽

Cited By ~ 1

Author(s):

SeyedArmin MotahariTabari ◽

Issa Shooshpasha

Keyword(s):

Mechanical Properties ◽

Direct Shear Test ◽

Shear Test ◽

Coarse Grained ◽

Direct Shear

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Effects of graphene thickness and length distribution on the mechanical properties of graphene networks: A coarse-grained molecular dynamics simulation

Applied Surface Science ◽

10.1016/j.apsusc.2021.151023 ◽

2021 ◽

pp. 151023

Author(s):

Qiang Bao ◽

Zhenyu Yang ◽

Zixing Lu ◽

Xiaofan He

Keyword(s):

Mechanical Properties ◽

Molecular Dynamics ◽

Molecular Dynamics Simulation ◽

Length Distribution ◽

Dynamics Simulation ◽

Coarse Grained ◽

Coarse Grained Molecular Dynamics

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Grain Refinement and Deformation Behavior of Ultrafine Grained Pd and Pd-Ag Alloys Produced by HPT

Materials Science Forum ◽

10.4028/www.scientific.net/msf.584-586.182 ◽

2008 ◽

Vol 584-586 ◽

pp. 182-187

Author(s):

Lilia Kurmanaeva ◽

Yulia Ivanisenko ◽

J. Markmann ◽

Ruslan Valiev ◽

Hans Jorg Fecht

Keyword(s):

Mechanical Properties ◽

Deformation Behavior ◽

Materials Science ◽

High Pressure Torsion ◽

Uniform Elongation ◽

Grain Structure ◽

Coarse Grained ◽

Ultrafine Grain ◽

Ultrafine Grained ◽

Ultrafine Grain Structure

Investigations of mechanical properties of nanocrystalline (nc) materials are still in interest of materials science, because they offer wide application as structural materials thanks to their outstanding mechanical properties. NC materials demonstrate superior hardness and strength as compared with their coarse grained counterparts, but very often they possess a limited ductility or show low uniform elongation due to poor strain hardening ability. Here, we present the results of investigation of the microstructure and mechanical properties of nc Pd and Pd-x%Ag (x=20, 60) alloys. The initially coarse grained Pd-x% Ag samples were processed by high pressure torsion, which resulted in formation of homogenous ultrafine grain structure. The increase of Ag contents led to the decrease of the resulted grain size and change in deformation behavior, because of decreasing of stacking fault energy (SFE). The samples with larger Ag contents demonstrated the higher values of hardness, yield stress and ultimate stress. Remarkably the uniform elongation had also increased with increase of strength.

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Microstructure, texture and mechanical properties of coarse-grained Mg–Gd–Y–Nd–Zr alloy processed by multidirectional forging

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2014.10.084 ◽

2015 ◽

Vol 623 ◽

pp. 62-68 ◽

Cited By ~ 67

Author(s):

Xiangsheng Xia ◽

Qiang Chen ◽

Zude Zhao ◽

Minglong Ma ◽

Xinggang Li ◽

...

Keyword(s):

Mechanical Properties ◽

Coarse Grained ◽

Multidirectional Forging ◽

Zr Alloy

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EFFECTS OF STOICHIOMETRY ON PROPERTIES OF DGEBF/DETDA EPOXY USING MOLECULAR DYNAMICS

10.12783/asc36/35845 ◽

2021 ◽

Author(s):

SAGAR PATIL ◽

MICHAEL OLAYA ◽

PRATHAMESH DESHPANDE ◽

MARIANNA MAIARÙ ◽

GREGORY ODEGARD

Keyword(s):

Mechanical Properties ◽

Molecular Dynamics ◽

Molecular Modeling ◽

Bulk Modulus ◽

Mass Density ◽

Strong Dependence ◽

Crosslinking Density ◽

Mechanical Deformation ◽

Epoxy System ◽

Reactive Interface

This article details the molecular modeling of full and off-stoichiometry models of the DGEBF/DETDA epoxy system using Molecular Dynamics to predict the mechanical properties as a function of the crosslinking density. The Reactive Interface Force Field (IFF-R) is implemented in this work to simulate mechanical deformation. The “fix bond/react” command in LAMMPS is used to simulate crosslinking between epoxy monomers. The results show that the predicted mass density, volumetric shrinkage, and bulk modulus have a strong dependence on the stoichiometry of the epoxy.

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Mechanical Properties and Deformation Mechanisms of Graphene Foams with Bi-Modal Sheet Thickness by Coarse-Grained Molecular Dynamics Simulations

Materials ◽

10.3390/ma14195622 ◽

2021 ◽

Vol 14 (19) ◽

pp. 5622

Author(s):

Shenggui Liu ◽

Mindong Lyu ◽

Chao Wang

Keyword(s):

Mechanical Properties ◽

Elastic Recovery ◽

Structural Connectivity ◽

High Stress ◽

Sheet Thickness ◽

Functional Materials ◽

Deformation Mechanisms ◽

Coarse Grained ◽

Graphene Sheets ◽

Graphene Foams

Graphene foams (GrFs) have been widely used as structural and/or functional materials in many practical applications. They are always assembled by thin and thick graphene sheets with multiple thicknesses; however, the effect of this basic structural feature has been poorly understood by existing theoretical models. Here, we propose a coarse-grained bi-modal GrF model composed of a mixture of 1-layer flexible and 8-layer stiff sheets to study the mechanical properties and deformation mechanisms based on the mesoscopic model of graphene sheets (Model. Simul. Mater. Sci. Eng. 2011, 19, 54003). It is found that the modulus increases almost linearly with an increased proportion of 8-layer sheets, which is well explained by the mixture rule; the strength decreases first and reaches the minimum value at a critical proportion of stiff sheets ~30%, which is well explained by the analysis of structural connectivity and deformation energy of bi-modal GrFs. Furthermore, high-stress regions are mainly dispersed in thick sheets, while large-strain areas mainly locate in thin ones. Both of them have a highly uneven distribution in GrFs due to the intrinsic heterogeneity in both structures and the mechanical properties of sheets. Moreover, the elastic recovery ability of GrFs can be enhanced by adding more thick sheets. These results should be helpful for us to understand and further guide the design of advanced GrF-based materials.

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