• Title/Summary/Keyword: Bishop theory

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Bishop theory and longitudinal vibration of nano-beams by two-phase local/nonlocal elasticity

  • Reza Nazemnezhad;Roozbeh Ashrafian;Alireza Mirafzal
    • Advances in nano research
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    • v.15 no.1
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    • pp.75-89
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    • 2023
  • In this paper, Bishop theory performs longitudinal vibration analysis of Nano-beams. Its governing equation, due to integrated displacement field and more considered primarily effects compared with other theories, enjoys fully completed status, and more reliable results as well. This article aims to find how Bishop theory and Two-phase elasticity work together. In other words, whether Bishop theory will be compatible with Two-phase local/nonlocal elasticity. Hamilton's principle is employed to derive governing equation of motion, and then the 6th order of Generalized Differential Quadrature Method (GDQM) as a constructive numerical method is utilized to attain the discretized two-phase formulation. To acquire a proper verification procedure, exact solution is prepared to be compared with current results. Furthermore, the effects of key parameters on the objective are investigated.

Free axial vibration analysis of axially functionally graded thick nanorods using nonlocal Bishop's theory

  • Nazemnezhad, Reza;Kamali, Kamran
    • Steel and Composite Structures
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    • v.28 no.6
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    • pp.749-758
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    • 2018
  • Free axial vibration of axially functionally graded (AFG) nanorods is studied by focusing on the inertia of lateral motions and shear stiffness effects. To this end, Bishop's theory considering the inertia of the lateral motions and shear stiffness effects and the nonlocal theory considering the small scale effect are used. The material properties are assumed to change continuously through the length of the AFG nanorod according to a power-law distribution. Then, nonlocal governing equation of motion and boundary conditions are derived by implementing the Hamilton's principle. The governing equation is solved using the harmonic differential quadrature method (HDQM), After that, the first five axial natural frequencies of the AFG nanorod with clamped-clamped end condition are obtained. In the next step, effects of various parameters like the length of the AFG nanorod, the diameter of the AFG nanorod, material properties, and the nonlocal parameter value on natural frequencies are investigated. Results of the present study can be useful in more accurate design of nano-electro-mechanical systems in which nanotubes are used.

On the Bishop Stress of Unsaturated Soils under the Low Level of Matric Suction (낮은 모관흡수력 수준에서 불포화토의 Bishop 응력에 관한 연구)

  • Oh, Se-Boong;Kim, Tae-Kyung
    • Journal of the Korean Geotechnical Society
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    • v.24 no.7
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    • pp.17-24
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    • 2008
  • In this study, the triaxial behaviour of an unsaturated soil was analyzed by Bishop stress descriptions. $K_0$ stress paths and those final values were independent of matric suctions after describing by the Bishop stress. The failure criteria could be defined uniquely by the Bishop stress and were also independent of matric suctions. In the low level of matric suctions the failure criteria have a linear relationship and the estimated criterion fits the measured accurately. The variable ${\chi}$ for describing the Bishop stress was a constant theoretically under the low level of matric suctions. The suction stress could be defined at zero deviatoric stress in the failure criteria and increased linearly with respect to matric suctions in both the theory and the experiments.

BISHOP'S PROPERTY (${\beta}$) AND SPECTRAL INCLUSIONS ON BANACH SPACES

  • Yoo, Jong-Kwang;Oh, Heung-Joon
    • Journal of applied mathematics & informatics
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    • v.29 no.1_2
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    • pp.459-468
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    • 2011
  • Let T ${\in}$ L(X), S ${\in}$ L(Y), A ${\in}$ L(X, Y) and B ${\in}$ L(Y, X) such that SA = AT, TB = BS, AB = S and BA = T. Then S and T shares the same local spectral properties SVEP, Bishop's property (${\beta}$), property $({\beta})_{\epsilon}$, property (${\delta}$) and and subscalarity. Moreover, the operators ${\lambda}I$ - T and ${\lambda}I$ - S have many basic operator properties in common.

Size dependent axial free and forced vibration of carbon nanotube via different rod models

  • Khosravi, Farshad;Simyari, Mahdi;Hosseini, Seyed A.;Tounsi, Abdelouahed
    • Advances in nano research
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    • v.9 no.3
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    • pp.157-172
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    • 2020
  • The aim of this present research is the effect of the higher-order terms of the governing equation on the forced longitudinal vibration of a nanorod model and making comparisons of the results with classical nonlocal elasticity theory. For this purpose, the free axial vibration along with forced one under the two various linear and harmonic axial concentrated forces in zigzag Single-Walled Carbon Nanotube (SWCNT) are analyzed dynamically. Three various theories containing the classical theory, which is called Eringen's nonlocal elasticity, along with Rayleigh and Bishop theories (higher-order theories) are established to justify the nonlocal behavior of constitutive relations. The governing equation and the related boundary conditions are derived from Hamilton's principle. The assumed modes method is adopted to solve the equation of motion. For the free axial vibration, the natural frequencies are calculated for the various values of the nonlocal parameter only based on Eringen's theory. The effects of the nonlocal parameter, thickness, length, and ratio of the excitation frequency to the natural frequency over time in dimensional and non-dimensional axial displacements are investigated for the first time.

On a clary theorem

  • Ko, Eungil
    • Bulletin of the Korean Mathematical Society
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    • v.33 no.1
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    • pp.29-33
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    • 1996
  • In this paper we shall generalize a Clary theorem by using the local spectral theory; If $ T \in L(H)$ has property $(\beta)$ and A is any operator such that $A \prec T$, then $\sigma(T) \subseteq \sigma(A)$.

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On the spectral propeties of multipliers

  • Yoo, Jong-Kwang
    • Communications of the Korean Mathematical Society
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    • v.12 no.4
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    • pp.911-920
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    • 1997
  • This note centers around the class M(A) of multipliers on a Gelfand algebra A. This class is a large subalgebra of the Banach algebra L(A). The aim of this note is to investigate some aspects concerning their local spectral properties of multipliers. In the last part of work we consider some applications to automatic continuity theory.

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Prediction of Deformation Texture for FCC Metals Using the Finite Element Method (유한요소법을 이용한 면심입방정금속의 변형 집합조직 예측)

  • 권재욱;정효태;오규환;이동녕
    • Transactions of Materials Processing
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    • v.3 no.2
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    • pp.229-242
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    • 1994
  • An approximate procedure based on a combination micro-macroscopic theories of plasticity for predicting the crystallographic texture during the plane strain forming of fcc metals has been developed. This procedure is divided into two steps. Firstly, we extract the history of the deformation gradient at all deformed elements with a elasto-plastic finite element method using isotropic plasticity model. Secondly, we use this deformation gradient history to predict the crystallographic deformation texture based on the Bishop-Hill theory. Renouard and Wintenberger' method is chosen for selecting the active slip systems. The predicted results have been compared with reported experimental results. The calculated results are in good agreement with their results.

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LOCAL SPECTRAL THEORY AND QUASINILPOTENT OPERATORS

  • YOO, JONG-KWANG
    • Journal of applied mathematics & informatics
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    • v.40 no.3_4
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    • pp.785-794
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    • 2022
  • In this paper we show that if A ∈ L(X) and R ∈ L(X) is a quasinilpotent operator commuting with A then XA(F) = XA+R(F) for all subset F ⊆ ℂ and 𝜎loc(A) = 𝜎loc(A + R). Moreover, we show that A and A + R share many common local spectral properties such as SVEP, property (C), property (𝛿), property (𝛽) and decomposability. Finally, we show that quasisimility preserves local spectrum.