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Multiscale Modeling and Mechanics of 2D Layered Crystals
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| 자료유형 | 학위논문 |
|---|---|
| 서명/저자사항 | Multiscale Modeling and Mechanics of 2D Layered Crystals. |
| 개인저자 | Zhao, Peng. |
| 단체저자명 | The Pennsylvania State University. Engineering Science and Mechanics. |
| 발행사항 | [S.l.]: The Pennsylvania State University., 2019. |
| 발행사항 | Ann Arbor: ProQuest Dissertations & Theses, 2019. |
| 형태사항 | 141 p. |
| 기본자료 저록 | Dissertations Abstracts International 80-12B. Dissertation Abstract International |
| ISBN | 9781392319116 |
| 학위논문주기 | Thesis (Ph.D.)--The Pennsylvania State University, 2019. |
| 일반주기 |
Source: Dissertations Abstracts International, Volume: 80-12, Section: B.
Publisher info.: Dissertation/Thesis. Advisor: Zhang, Sulin. |
| 이용제한사항 | This item must not be added to any third party search indexes.This item must not be sold to any third party vendors. |
| 요약 | The two-dimensional (2D) material library has been expanding ever since the first successful isolation of graphene. Beyond the excessive research on each type graphene-like crystal, vertically stacked 2D materials, or, van der Waals heterostructures, has attracted tremendous research interests due to those unique properties and potentials they promise. Such a great push, however, requires for the in-depth understanding of the different stacking geometries and material choices, and the fundamental physical mechanisms behind them, which enables developing new device concepts and applications which would have been difficult to achieve with other material platforms.From the mechanics' point of view, this dissertation contributes to the multiscale modeling of stacked 2D materials. The ease of out-of-plane bending in 2D layers allows new types of low-energy linear defects that are absent from bulk crystals: wrinkles, ripples and crumples that arise from interlayer lattice mismatch, providing a rich mechanical environment due to the geometrical challenge of accommodating the curvature energy and the interlayer interactions. Though detailed atomistic simulations in microscale, the morphology, energetics, mobility, and controllability of such defect in stacked 2D materials are investigated, which provides concepts of the design of novel origami-based structures.A quasi-continuum theory for analysis of mechanics of stacked 2D system is presented. The traditional methods of crystal elasticity are extended by introducing the atomic resolution to deal with registry effect of crystal structures. A homogenized finite crystal elasticity modeling is firstly developed, as an extension of the exponential Cauchy-Born rule. The model enables simulations for 2D stacked heterostructures. Borrowing the idea of diffusive molecular dynamics (DMD) and phase field crystal (PFC), a generalization of the variational Gaussian method on non-bonded energy, the Gaussian averaged interlayer potential is developed and is the key to the theory.This methodology allows us to formulate a quasi-continuum relation for continua of reduced dimensionality (lines, surfaces) exclusively regarding the underlying lattice structure and possess the same crystal symmetry. These models are shown to very accurately mimic the discrete parent model within full atomic resolutions. The theory is applied to the mechanics of bilayer graphene. Since the continuum model is discretized with finite element approximation, it provides a computationally advantageous alternative to atomistic calculations. Besides, the resolution can also be tuned by altering the number of grids and length scale, indicating multi-scale modeling capabilities. |
| 일반주제명 | Mechanics. |
| 언어 | 영어 |
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: 이 자료의 원문은 한국교육학술정보원에서 제공합니다. |
