VNU-UET Repository: No conditions. Results ordered -Date Deposited. 2023-09-29T01:24:48ZEPrintshttp://eprints.uet.vnu.edu.vn/images/sitelogo.pnghttps://eprints.uet.vnu.edu.vn/eprints/2017-12-25T03:48:08Z2017-12-25T03:48:08Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/2825This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/28252017-12-25T03:48:08ZThermomechanical buckling and post-buckling of cylindrical shell with functionally graded coatings and reinforced by stringersThe cylindrical shells reinforced by stringers have been widely used in modern engineering structures such as storage tanks, missile, submarine hull, oil-transmitting pipeline, etc. In this present article, the thermomechanical buckling and post-buckling behaviors of a cylindrical shell with functionally graded (FG) coatings are investigated by an analytical approach. The cylindrical shell is reinforced by outside stringers under torsional load in the thermal environment. The layers of FG coatings are assumed to be made by functionally graded materials (FGMS) combining of ceramic and metal phases and the core of the shell is made from homogeneous material. The classical shell theory based on the von-Karman assumptions is used to model the thin cylindrical shell. Using Galerkin's procedure and Airy stress function, the governing equations can be solved to obtain the closed-form solution for the critical buckling load and postbuckling load-deflection curves of simply supported shells. Moreover, many important parametric studies of stringers, temperature field, material volume fraction index, the thickness of metal layer, etc. are taken into investigation. According to numerical examples, it is revealed that the outside strings have considerably impact on thermomechanical buckling and postbuckling behaviors of the shells.Toan Thang PhamDinh Duc Nguyenducnd@vnu.edu.vnThoi Trung Nguyen2017-12-20T04:55:12Z2017-12-20T04:55:12Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/2823This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/28232017-12-20T04:55:12ZStatic response and free vibration of functionally graded carbon nanotube-reinforced composite rectangular plates resting on Winkler–Pasternak elastic foundationsIn the present article, static response and free vibration of functionally graded carbon nanotube
reinforced composite (FG-CNTRC) rectangular plate resting on Winkler–Pasternak elastic foundations
using an analytical approach are studied. The rectangular plates are reinforced by single-walled carbon
nanotubes (SWCNTs) which are assumed to be graded through the thickness direction with four types
of distributions. The mathematical model of the FG-CNTRC plate is developed based on the first-order
shear deformation plate theory (FSDT) and Hamilton principle. By using Navier solution, the governing
equations are solved to obtain the central deflection and the natural frequency parameters. Several
examples are verified to have higher accuracy than those from the previous method in the literature.
Also, the effects of different parameters on static response and natural frequency of FG-CNTRC plate are
highlighted by solving numerous examples. Finally, these new results may serve as benchmarks for future
investigations.Dinh Duc Nguyenducnd@vnu.edu.vnJaehong LeeThoi Trung NguyenToan Thang Pham2017-03-06T04:23:25Z2017-03-06T04:23:25Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/2418This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/24182017-03-06T04:23:25ZEffects of variable thickness and imperfection on nonlinear buckling of Sigmoid-functionally graded cylindrical panelsToan Thang PhamDinh Duc Nguyenducnd@vnu.edu.vnThoi Trung Nguyen2016-05-26T08:58:29Z2016-05-26T08:59:13Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1697This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/16972016-05-26T08:58:29ZNonlinear response of imperfect eccentrically stiffened ceramic-metal-ceramic S-FGM thin circular cylindrical shells surrounded on elastic foundations under uniform radial loadDinh Duc Nguyenducnd@vnu.edu.vnToan Thang Pham2015-11-26T06:05:39Z2015-11-26T06:06:36Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1218This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/12182015-11-26T06:05:39ZNonlinear Response of Imperfect Eccentrically Stiffened Ceramic-Metal-Ceramic FGM Circular Cylindrical Shells Surrounded on Elastic Foundations and Subjected to Axial CompressionDinh Duc Nguyenducnd@vnu.edu.vnToan Thang Pham2015-11-24T07:52:50Z2015-11-24T07:54:12Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1214This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/12142015-11-24T07:52:50ZNonlinear Response of Imperfect Eccentrically Stiffened Ceramic-Metal-Ceramic S-FGM Thin Circular Cylindrical Shells Surrounded on Elastic Foundations under Uniform Radial LoadDinh Duc Nguyenducnd@vnu.edu.vnToan Thang Pham2015-11-24T07:39:24Z2015-11-24T07:42:10Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1216This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/12162015-11-24T07:39:24ZNonlinear Buckling of Imperfect Eccentrically Stiffened Metal-Ceramic-Metal S-FGM Thin Circular Cylindrical Shells with Temperature-Dependent Properties in Thermal EnvironmentsIn this paper, an analytical approach is presented to investigate the nonlinear static buckling for imperfect eccentrically stiffened functionally graded thin circular cylindrical shells with temperature-dependent properties surrounded on elastic foundation in thermal environment. Both shells and stiffeners are deformed simultaneously due to temperature. Material properties are graded in the thickness direction according to a Sigmoid power law distribution in terms of the volume fractions of constituents (S-FGM) with metal–ceramic–metal layers. The Lekhnitsky smeared stiffeners technique with Pasternak type elastic foundation, stress function and the Bubnov–Galerkin method are applied. Numerical results are given for evaluating effects of temperature, material and geometrical properties, elastic foundations and eccentrically outside stiffeners on the buckling and post-buckling of the S-FGM shells. The obtained results are validated by comparing with those in the literature.Dinh Duc Nguyenducnd@vnu.edu.vnToan Thang Pham2015-11-19T08:43:16Z2015-11-19T08:43:55Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1209This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/12092015-11-19T08:43:16ZNonlinear buckling of higher deformable S-FGM thick circular cylindrical shells with metal-ceramic-metal layers surrounded on elastic foundations in thermal environmentAn analytical approach on the nonlinear response of thick functionally graded circular cylindrical shells with temperature independent material property surrounded on elastic foundations subjected to mechanical and thermal loads is presented. Material properties are graded in the thickness direction according to a Sigmoid power law distribution in terms of the volume fractions of constituents (S-FGM). The formulations are based on the third order shear deformation shell theory taking into account von Karman nonlinearity, initial geometrical imperfection and Pasternak type elastic foundation. By applying Galerkin method and using stress function, explicit relations of thermal load–deflection curves of the S-FGM shells are determined. Detailed parametric studies are carried out to investigate effects of volume fraction index, material properties and geometrical shapes, axial compressions and thermal load, foundation stiffness and imperfection on nonlinear buckling behaviors of S-FGM thick circular cylindrical shells. The present analysis is validated by comparing results with other publications.Dinh Duc Nguyenducnd@vnu.edu.vnToan Thang PhamTrong Dao NguyenVan Tac Hoang2015-08-28T09:51:07Z2015-08-31T08:03:09Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1379This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/13792015-08-28T09:51:07ZMonitoring the Oscillation Frequency Drift of an Optoelectronic Oscillator with a Vector Network AnalyzerThe classical structure of an optoelectronic oscillator (OEO) is based on a long optical fiber loop creating a delay line with very low insertion loss. The oscillation frequency is proportional to the reciprocal of the propagation delay which depends on temperature by the way of the effective refractive index of the fiber. In case of a long fiber loop, even a small change of the temperature can induce an oscillation frequency drift. In this paper, a system based on a vector network analyzer (VNA) is proposed to monitor the oscillation frequency drift with a minimum of extra optical components. There is a good correlation between the phase evolution determined by the VNA and the OEO frequency drift. Knowing the drift it is possible to correct results obtained from the OEO used as an optical path measurement tool for either distance or refractive index variation detection.Toan Thang PhamGia-Duong Bachduongbg@vnu.edu.vnVan Yem VuI Ledoux-RakBernard Journet2015-08-14T06:53:11Z2015-08-14T07:51:56Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1230This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/12302015-08-14T06:53:11ZNonlinear Analysis on Flutter of S-FGM Thin Circular Cylindrical Shells with Metal-Ceramic-Metal Layers Surrounded on Elastic Foundations using Ilyushin Supersonic Aerodynamic TheoryDinh Duc Nguyenducnd@vnu.edu.vnB.E. PobedryaHuy Bich DaoToan Thang Pham2015-08-05T04:43:30Z2015-08-05T04:43:30Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1208This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/12082015-08-05T04:43:30ZNonlinear dynamic response and vibration of shear deformable imperfect eccentrically stiffened S-FGM circular cylindrical shells surrounded on elastic foundationsThis paper presents an analytical approach to investigate the nonlinear dynamic response and vibration of imperfect eccentrically stiffened functionally graded thick circular cylindrical shells surrounded on elastic foundations using both the first order shear deformation theory and stress function with full motion equations (not using Volmir's assumptions). Material properties are graded in the thickness direction according to a sigmoid power law distribution (S-FGM) in terms of the volume fractions of constituents with metal–ceramic–metal layers. The S-FGM shells are subjected to mechanical and damping loads. Numerical results for dynamic response of the shells are obtained by Runge–Kutta method. The results show the influences of geometrical parameters, the volume fractions of metal–ceramic–metal layers, imperfections, the elastic foundations, eccentrically stiffeners, pre-loaded axial compression and damping loads on the nonlinear dynamic response and nonlinear vibration of functionally graded cylindrical shells. The proposed results are validated by comparing with other results reported in the literature.Dinh Duc Nguyenducnd@vnu.edu.vnToan Thang Pham2013-01-25T07:17:18Z2013-06-29T04:17:02Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/129This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/1292013-01-25T07:17:18ZElectro-Optic Modulator Drift Compensation based on DSP SystemToan Thang PhamVan Yem VuGia-Duong Bachduongbg@vnu.edu.vnBernard Journet