東華大學圖書館 |

Language: English

Help

回圖書館首頁

手機版館藏查詢

Back

Switch To: Labeled | MARC Mode | ISBD

Assessing the Mechanical Behavior of...

Tao, Weiwei.

Linked to FindBook

Google Book

Amazon

博客來

Assessing the Mechanical Behavior of Proteins and Metal Nanowires Using Long Timescale Atomistic Simulations.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Assessing the Mechanical Behavior of Proteins and Metal Nanowires Using Long Timescale Atomistic Simulations./
Author:	Tao, Weiwei.
Published:	Ann Arbor : ProQuest Dissertations & Theses, : 2018,
Description:	183 p.
Notes:	Source: Dissertation Abstracts International, Volume: 80-03(E), Section: B.
Contained By:	Dissertation Abstracts International80-03B(E).
Subject:	Mechanical engineering. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10825727
ISBN:	9780438607699

Assessing the Mechanical Behavior of Proteins and Metal Nanowires Using Long Timescale Atomistic Simulations.
Tao, Weiwei.

Assessing the Mechanical Behavior of Proteins and Metal Nanowires Using Long Timescale Atomistic Simulations. - Ann Arbor : ProQuest Dissertations & Theses, 2018 - 183 p.

Source: Dissertation Abstracts International, Volume: 80-03(E), Section: B.

Thesis (Ph.D.)--Boston University, 2018.

Classical molecular dynamics (MD) simulations have been widely used to study the physical properties of nanomaterials. However, MD suffers from the well-known drawback where it cannot, in the absence of special high-performance computing environments, simulate processes that take longer than microseconds. Nevertheless, many important processes in various fields of science and engineering take place on time scales that cannot be reached by MD. For example, while MD simulations have been used extensively to study the plasticity of nanostructures such as proteins and nanowires, their time scale limitations have prevented the study of the deformation mechanisms at experimentally-relevant forces, time scales and strain rates. In this thesis, a generic history-penalized self-learning metabasin escape (SLME) algorithm, which efficiently explores the potential energy surface, is utilized to overcome this issue by studying three canonical problems of interest: the unfolding of biological proteins under experimentally-relevant mechanical forces; the strain-rate-dependent plastic deformation mechanisms of bicrystalline FCC metal nanowires, and finally the constant stress (creep-induced) plastic deformation of single crystalline metallic nanowires at experimental time scales. The SLME method is first utilized to study the force-induced unfolding of biological proteins. The long time scale simulations not only provide atomistic details of time-dependent structural evolution under experimentally-relevant forces, but also show novel intermediate states that cannot be observed in MD simulations, which sheds new insight into the understanding of protein unfolding dynamics. This method is then utilized to investigate the strain rate effect on the plastic mechanisms of bicrystalline metal nanowires. A strain-rate-dependent incipient plasticity and yielding transition for bicrystalline metal nanowires at experimentally-relevant strain rates is observed. This transition leads to a ductile-to-brittle transition in failure mode, which is driven by differences in dislocation activity and grain boundary mobility at low strain rate as compared to the high strain rate case. Finally, the SLME method is also utilized to study the creep behavior of single crystalline metal nanowires at experimental time scales. Both copper and silver nanowires show significantly increased ductility and superplasticity under experimentally-relevant creep stresses, where the superplasticity is driven by a thermally-activated transition in defect nucleation from twinning to trailing partial dislocations at the micro or millisecond timescale.

ISBN: 9780438607699Subjects--Topical Terms:

649730
Mechanical engineering.

Assessing the Mechanical Behavior of Proteins and Metal Nanowires Using Long Timescale Atomistic Simulations.
LDR:03630nmm a2200313 4500 001 2200250
005 20181214130636.5
008 201008s2018 ||||||||||||||||| ||eng d
020 $a 9780438607699
035 $a (MiAaPQ)AAI10825727
035 $a (MiAaPQ)bu:13966
035 $a AAI10825727
040 $a MiAaPQ $c MiAaPQ
100 1 $a Tao, Weiwei. $3 3426999
245 1 0 $a Assessing the Mechanical Behavior of Proteins and Metal Nanowires Using Long Timescale Atomistic Simulations.
260 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 2018
300 $a 183 p.
500 $a Source: Dissertation Abstracts International, Volume: 80-03(E), Section: B.
500 $a Adviser: Harold S. Park.
502 $a Thesis (Ph.D.)--Boston University, 2018.
520 $a Classical molecular dynamics (MD) simulations have been widely used to study the physical properties of nanomaterials. However, MD suffers from the well-known drawback where it cannot, in the absence of special high-performance computing environments, simulate processes that take longer than microseconds. Nevertheless, many important processes in various fields of science and engineering take place on time scales that cannot be reached by MD. For example, while MD simulations have been used extensively to study the plasticity of nanostructures such as proteins and nanowires, their time scale limitations have prevented the study of the deformation mechanisms at experimentally-relevant forces, time scales and strain rates. In this thesis, a generic history-penalized self-learning metabasin escape (SLME) algorithm, which efficiently explores the potential energy surface, is utilized to overcome this issue by studying three canonical problems of interest: the unfolding of biological proteins under experimentally-relevant mechanical forces; the strain-rate-dependent plastic deformation mechanisms of bicrystalline FCC metal nanowires, and finally the constant stress (creep-induced) plastic deformation of single crystalline metallic nanowires at experimental time scales. The SLME method is first utilized to study the force-induced unfolding of biological proteins. The long time scale simulations not only provide atomistic details of time-dependent structural evolution under experimentally-relevant forces, but also show novel intermediate states that cannot be observed in MD simulations, which sheds new insight into the understanding of protein unfolding dynamics. This method is then utilized to investigate the strain rate effect on the plastic mechanisms of bicrystalline metal nanowires. A strain-rate-dependent incipient plasticity and yielding transition for bicrystalline metal nanowires at experimentally-relevant strain rates is observed. This transition leads to a ductile-to-brittle transition in failure mode, which is driven by differences in dislocation activity and grain boundary mobility at low strain rate as compared to the high strain rate case. Finally, the SLME method is also utilized to study the creep behavior of single crystalline metal nanowires at experimental time scales. Both copper and silver nanowires show significantly increased ductility and superplasticity under experimentally-relevant creep stresses, where the superplasticity is driven by a thermally-activated transition in defect nucleation from twinning to trailing partial dislocations at the micro or millisecond timescale.
590 $a School code: 0017.
650 4 $a Mechanical engineering. $3 649730
650 4 $a Computer engineering. $3 621879
650 4 $a Molecular physics. $3 3174737
690 $a 0548
690 $a 0464
690 $a 0609
710 2 $a Boston University. $b Mechanical Engineering ENG. $3 3181571
773 0 $t Dissertation Abstracts International $g 80-03B(E).
790 $a 0017
791 $a Ph.D.
792 $a 2018
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10825727