Cylindrical Bending Vibration of Multiple Graphene SheetSystems Embedded in an Elastic Medium
| Autor: | Yen-JungChen, 陳彥蓉 |
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| Rok vydání: | 2019 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 107 An asymptotic nonlocal elasticity theory for cylindrical bending vibration analysis of simply-supported, Nl-layered, and uniformly- or nonuniformly-spaced, graphene sheet (GS) systems embedded in an elastic medium is developed by using the Eringen nonlocal elasticity theory and multiple time scale method. Both the interactions between the topmost and bottommost GSs and their surrounding medium and the interactions between each pair of adjacent GSs are modelled as one-parameter Winkler models with different stiffness coefficients. In the formulation, the small length scale effect is introduced to nonlocal constitutive equations using a nonlocal parameter, and then the nondimensionalization, asymptotic expansion, and successive integration mathematical processes are performed for a typical GS. After assembling the motion equations for each individual GS to form those of the multiple GS system, recurrent sets of motion equations can be obtained for various order problems. Nonlocal multiple classical plate theory (CPT) is derived as a first-order approximation of the current nonlocal plane strain problem, and the motion equations for higher-order problems retain the same differential operators as those of nonlocal multiple CPT, although with different nonhomogeneous terms. Some nonlocal plane strain solutions for the natural frequency parameters of the multiple GS system with and without being embedded in the elastic medium and their corresponding mode shapes are presented to demonstrate the performance of the asymptotic nonlocal elasticity theory. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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