Micro/meso-scale computational study of dislocation-stacking-fault tetrahedron interactions in copper

In a carbon-free economy, nuclear power will surely play a fundamental role as a clean and cost-competitive energy source. However, new-generation nuclear concepts involve temperature and irradiation conditions for which no experimental facility exists, making it exceedingly difficult to predict structural materials performance and lifetime. Although the gap with real materials is still large, advances in computing power over the last decade have enabled the development of accurate and efficient numerical algorithms for materials simulations capable of probing the challenging conditions expected in future nuclear environments. One of the most important issues in metallic structural materials is the degradation of their mechanical properties under irradiation. Mechanical properties are intimately related to the glide resistance of dislocations, which can be increased severalfold due to irradiation-produced defects. Here, we present a combined multiscale study of dislocation-irradiation obstacle interactions in a model system (Cu) using atomistic and dislocation dynamics simulations. Scaling laws generalizing material behavior are extracted from our results, which are then compared with experimental measurements of irradiation hardening in Cu, showing good agreement.

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Pointing Errors of Large Telescopes Due to Wind

International Astronomical Union Colloquium ◽

10.1017/s0252921100108371 ◽

1984 ◽

Vol 79 ◽

pp. 177-181

Author(s):

Bobby L. Ulich

Keyword(s):

Mechanical Properties ◽

Wind Speed ◽

Scaling Laws ◽

Tracking Error ◽

Structural Materials ◽

Pointing Errors ◽

Direct Measurements ◽

Large Telescopes ◽

Mirror Telescope

AbstractScaling laws are presented which show the dependence of the tracking error of large telescopes on structural materials, mechanical properties and dimensions of the mount, and wind speed. Based on direct measurements on the Multiple Mirror Telescope, predictions are made for future very large telescopes. It is shown that good tracking can be achieved most of the time even without a traditional dome to block the wind, and this may result in better images by eliminating “dome seeing”.

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Mechanical properties of Graphene: Molecular dynamics simulations correlated to continuum based scaling laws

Computational Materials Science ◽

10.1016/j.commatsci.2016.08.016 ◽

2016 ◽

Vol 125 ◽

pp. 319-327 ◽

Cited By ~ 25

Author(s):

B. Javvaji ◽

P.R. Budarapu ◽

V.K. Sutrakar ◽

D. Roy Mahapatra ◽

M. Paggi ◽

...

Keyword(s):

Mechanical Properties ◽

Molecular Dynamics ◽

Molecular Dynamics Simulations ◽

Scaling Laws ◽

Dynamics Simulations

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Mechanical anisotropy of two-dimensional metamaterials: a computational study

Nanoscale Advances ◽

10.1039/c9na00312f ◽

2019 ◽

Vol 1 (8) ◽

pp. 2891-2900 ◽

Cited By ~ 1

Author(s):

Ning Liu ◽

Mathew Becton ◽

Liuyang Zhang ◽

Keke Tang ◽

Xianqiao Wang

Keyword(s):

Mechanical Properties ◽

Molecular Dynamics ◽

Molecular Dynamics Simulations ◽

Computational Study ◽

2D Materials ◽

Mechanical Anisotropy ◽

Coarse Grained ◽

Two Dimensional ◽

Geometrical Factors ◽

Dynamics Simulations

Mechanical properties, especially negative Poisson's, of 2D sinusoidal lattice metamaterials based on 2D materials depends highly on both geometrical factors and tuned mechanical anisotropy according to our generic coarse-grained molecular dynamics simulations.

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Grain-size dependence of mechanical properties in polycrystalline boron-nitride: a computational study

Physical Chemistry Chemical Physics ◽

10.1039/c5cp03460d ◽

2015 ◽

Vol 17 (34) ◽

pp. 21894-21901 ◽

Cited By ~ 26

Author(s):

Matthew Becton ◽

Xianqiao Wang

Keyword(s):

Mechanical Properties ◽

Molecular Dynamics ◽

Grain Size ◽

Boron Nitride ◽

Molecular Dynamics Simulations ◽

Failure Mechanism ◽

Size Dependence ◽

Computational Study ◽

Grain Sizes ◽

Dynamics Simulations

Molecular dynamics simulations are performed to investigate the mechanical properties and failure mechanism of polycrystalline boron nitride sheet with various grain sizes.

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Multiscale Modeling of Irradiation Induced Hardening in a-Fe, Fe-Cr and Fe-Ni Systems

MRS Proceedings ◽

10.1557/proc-1264-bb06-05 ◽

2010 ◽

Vol 1264 ◽

Cited By ~ 4

Author(s):

Ioannis Mastorakos ◽

Ngoc Le ◽

Melody Zeine ◽

Hussein M Zbib ◽

Moe Khaleel

Keyword(s):

Md Simulations ◽

Structural Materials ◽

Dislocation Dynamics ◽

Multiscale Approach ◽

Helium Bubbles ◽

Degradation Of Materials ◽

Property Changes ◽

Dislocation Defects ◽

New Generation ◽

Radiation Conditions

AbstractStructural materials in the new Generation IV reactors will operate in harsh radiation conditions coupled with high levels of hydrogen and helium production, thus experiencing severe degradation of mechanical properties. The development of structural materials for use in such a hostile environment is predicated on understanding the underlying physical mechanisms responsible for microstructural evolution along with corresponding dimensional instabilities and mechanical property changes. As the phenomena involved are very complex and span in several length scales, a multiscale approach is necessary in order to fully understand the degradation of materials in irradiated environments. The purpose of this work is to study the behavior of Fe systems (namely a-Fe, Fe-Cr and Fe-Ni) under irradiation using both Molecular Dynamics (MD) and Dislocation Dynamics (DD) simulations. Critical information is passed from the atomistic (MD) to the microscopic scale (DD) in order to study the degradation of the material under examination. In particular, information pertaining to the dislocation-defects (such as voids, helium bubbles and prismatic loops) interactions is obtained from MD simulations. Then this information is used by DD to simulate large systems with high dislocation and defect densities.

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Multiscale Modeling of Irradiation Induced Hardening in Iron Alloys

MRS Proceedings ◽

10.1557/opl.2012.1424 ◽

2012 ◽

Vol 1444 ◽

Author(s):

Ioannis N. Mastorakos ◽

Hussein M. Zbib ◽

Dongsheng Li ◽

Mohamed A. Khaleel ◽

Xin Sun

Keyword(s):

Iron Alloys ◽

Dislocation Dynamics ◽

Multiscale Approach ◽

Helium Bubbles ◽

Physical Mechanisms ◽

Degradation Of Materials ◽

Property Changes ◽

Dynamics Simulations ◽

New Generation ◽

Radiation Conditions

ABSTRACTStructural materials in the new Generation IV reactors will operate in harsh radiation conditions coupled with high levels of hydrogen and helium production and will experience severe degradation of mechanical properties. Therefore, understanding of the physical mechanisms responsible for the microstructural evolution and corresponding mechanical property changes is critical. As the involved phenomena are very complex and span in several length scales, a multiscale approach is necessary in order to fully understand the degradation of materials in irradiated environments. In previous work, we used molecular dynamics simulations to develop critical rules for the mobility of dislocations in various iron alloys and their interaction with several types of defects that include, among others, helium bubbles and grain boundaries. In this work, Dislocation Dynamics simulations of iron alloys are used to study the mechanical behavior and the degradation under irradiation of large systems with high dislocation and defect densities.

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MECHANISMS OF RADIATION DAMAGE AND DEVELOPMENT OF STRUCTURAL MATERIALS FOR OPERATING AND ADVANCED NUCLEAR REACTORS

10.46813/2021-135-003 ◽

2021 ◽

pp. 3-20

Author(s):

V.N. Voyevodin ◽

G.D. Tolstolutskaya ◽

M.A. Tikhonovsky ◽

A.S. Kuprin ◽

A.S. Kalchenko

Keyword(s):

Radiation Damage ◽

Nuclear Power ◽

Nuclear Reactor ◽

Structural Materials ◽

Radiation Resistant ◽

Properties Of Materials ◽

Radiation Material ◽

New Generation ◽

High Degree

Safety of nuclear reactor (NR) and economic of nuclear power are determined to high degree by structural materials. Study of reasons of change of physical-mechanical properties of materials and of their dimensional stability under irradiation; determination of operation life of elements of nuclear power energetic assemblies in different conditions, selection and development of prospective materials with high radiation resistance are the main objectives of radiation material science. In the presented paper, mechanisms of radiation damage of structural materials for nuclear power and problems of development of radiation-resistant materials for operating and advanced NR of new generation are examined.

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Bonded Force Constant Derivation of Lysine-Arginine Cross-linked Advanced Glycation End-Products

10.26434/chemrxiv.5891602.v2 ◽

2018 ◽

Author(s):

Anthony Nash ◽

Nora H de Leeuw ◽

Helen L Birch

Keyword(s):

Molecular Dynamics ◽

Force Constant ◽

Computational Study ◽

Force Constants ◽

Quantum Mechanical ◽

Advanced Glycation ◽

Partial Charges ◽

Cross Links ◽

Complete Set ◽

Dynamics Simulations

<div> <div> <div> <p>The computational study of advanced glycation end-product cross- links remains largely unexplored given the limited availability of bonded force constants and equilibrium values for molecular dynamics force fields. In this article, we present the bonded force constants, atomic partial charges and equilibrium values of the arginine-lysine cross-links DOGDIC, GODIC and MODIC. The Hessian was derived from a series of <i>ab initio</i> quantum mechanical electronic structure calculations and from which a complete set of force constant and equilibrium values were generated using our publicly available software, ForceGen. Short <i>in vacuo</i> molecular dynamics simulations were performed to validate their implementation against quantum mechanical frequency calculations. </p> </div> </div> </div>

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Multiscale Methods for the Design of Structural Materials from First Principles: Systematic Search for New Nanostructures with Unprecedented Mechanical Properties

10.21236/ada564375 ◽

2012 ◽

Author(s):

Richard D. James ◽

Traian Dumitrica ◽

Kaushik Dayal

Keyword(s):

Mechanical Properties ◽

First Principles ◽

Structural Materials ◽

Multiscale Methods ◽

Systematic Search

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Liquid dibromomethane under pressure: a computational study

Physical Chemistry Chemical Physics ◽

10.1039/d0cp06458k ◽

2021 ◽

Vol 23 (4) ◽

pp. 2964-2971

Author(s):

Bernadeta Jasiok ◽

Mirosław Chorążewski ◽

Eugene B. Postnikov ◽

Claude Millot

Keyword(s):

Molecular Dynamics ◽

Molecular Dynamics Simulations ◽

Thermophysical Properties ◽

Computational Study ◽

Thermal Expansivity ◽

Dynamics Simulations ◽

Isobaric Thermal Expansivity

Thermophysical properties of liquid dibromomethane are investigated by molecular dynamics simulations between 268 and 328 K at pressures up to 3000 bar. Notably, the isotherms of the isobaric thermal expansivity cross around 800 bar.

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