VNU-UET Repository: No conditions. Results ordered -Date Deposited. 2023-05-28T12:25:17ZEPrintshttp://eprints.uet.vnu.edu.vn/images/sitelogo.pnghttps://eprints.uet.vnu.edu.vn/eprints/2017-01-04T07:18:24Z2017-01-04T07:18:24Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/2222This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/22222017-01-04T07:18:24ZInfluence of natural convection on beam propagation in fluidic optical deviceByunggi KimHong Duc Doandoan.hd.amsl.eng@vnu.edu.vnKazuyoshi Fushinobu2016-12-31T10:12:13Z2016-12-31T10:12:13Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/2349This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/23492016-12-31T10:12:13ZA New Approach to Predictive Control a Permanent Magnet Synchronous Motor fed by a Matrix ConverterIn this paper, a new approach to predictive control for speed control of a permanent magnet synchronous motor fed by a matrix converter is presented. The principle of this approach is to extend the possibilities of control by offering additional virtual vectors and to find the vector which minimizes the cost function. This process includes two main steps: first one will determine the location of vector in space vector and the second one will calculate the module of this voltage vector. In detail, a discrete mathematic model of drive system is built to predict the behaviors in the next step under a set of finite control states (FCS). This set will include not only eight real voltage vector from a three-phase two-level matrix converter but also the virtual voltage vectors. Predictive controller optimizes a predefined cost function in order to find a voltage vector giving the best result. Space vector modulation (SVM) technique will be used to generate the found voltage vector. The whole system has been modeled and simulated by using MATLAB and SIMULINK software to verify the performance of proposed method under different load and speed conditions. Results also are compared with classic direct predictive control about fundamental value and total harmonic distortion (THD) to highlight the improvement.Ngoc Linh Nguyennlnguyen@vnu.edu.vn2016-12-27T07:18:34Z2016-12-27T07:18:34Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/2287This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/22872016-12-27T07:18:34ZNonlinear stability analysis of thin FGM annular spherical shells on elastic foundations under external pressure and thermal loadsThi Thuy Anh Vuvuanhthuy206@gmail.comHuy Bich DaoDinh Duc Nguyenducnd@vnu.edu.vn2016-07-18T03:21:28Z2016-07-18T03:21:58Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1794This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/17942016-07-18T03:21:28ZUltrasonic Doppler velocity profile measurement of single- and two-phase flows using spike excitationIn the article, the application of the electrical spike, instead of the tone-burst, to the ultrasonic pulsed-Doppler velocity profiling the first time is presented. To generate ultrasound, the ultrasonic sensor is excited by the spike. For the Doppler method, the spike excitation was not used previously. It has been used with wideband signal processing methods. In our study, first, the fluid-velocity profile measurement using spike excitation has been carried out for single-phase pipe flow. The received data have been validated by the logarithmic law of the wall, for turbulent flow regime. The flow rate calculated by using the mean velocity profile well coincides with the flow-meter data. Furthermore, the spike signal and the Doppler method are used in the multiwave ultrasonic velocity profile (UVP) method, for the bubbly flow measurement. The experiments show that, if the spike signal is slowly damped, the generated ultrasonic wave is similar to the tone-burst that is required for the Doppler method, but in this case, usually the pulse length is smaller and depends on the damping and sensor characteristics. The autocorrelation technique is used for echo signal processing. The derived UVP systems inherit the advantages from both the spike excitation and Doppler method.Tat Thang NGUYENHideki MURAKAWANobuyoshi TSUZUKINgoc Hai DUONGHiroshige KIKURA2016-07-13T10:01:43Z2016-07-13T10:02:20Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1793This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/17932016-07-13T10:01:43ZMeasurement of the condensation rate in subcooled flow boiling by using two ultrasonic frequenciesTat Thang NguyenTSUZUKI NobuyoshiMURAKAWA HidekiNgoc Hai DuongKIKURA Hiroshige2016-07-11T12:24:58Z2016-07-11T12:51:18Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1791This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/17912016-07-11T12:24:58ZDynamic analysis of a cracked beam-like bridge subjected to earthquake and moving vehicleThis paper presents the influence of a crack on the dynamic behavior of a beam-type bridge subjected to separately or simultaneously a moving vehicle and earthquake excitation. In this study, the bridge is modelled as a 3D beam by the finite element method. The stiffness matrix of a cracked beam element with rectangular section adopted from fracture mechanics is presented. The influences of crack appearance time, crack location, crack depth, and vehicle speed on the dynamic response of the bridge are investigated. When a crack is induced during external excitation the stiffness of the structure is changed leading to a change in natural frequencies during vibration. This change in the frequency is analysed by wavelet spectrum, a time-frequency analysis which can examine locally a signal in both time and frequency domains. The relationship between the crack depth and the instantaneous frequency (IF) of the structure is established which may prove useful for assessment of the crack depth. Numerical simulation results are presented to investigate the efficiency of the method.Viet Khoa Nguyen2016-07-06T06:32:50Z2016-07-06T06:33:28Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1789This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/17892016-07-06T06:32:50Z1/3 SUBHARMONIC RESPONSE OF DUFFING OSCILLATOR UNDER PERIODIC AND RANDOM EXCITATIONSDong Anh NguyenL. Zakovorotny V.N. Hao D.X. Chiem N.2016-07-06T06:32:06Z2016-07-06T06:32:37Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1787This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/17872016-07-06T06:32:06ZGlobal–local mean square error criterion for equivalent linearization of nonlinear systems under random excitationThe paper presents a dual approach with respect to the local mean square error criterion to multi-degree-of-freedom nonlinear systems under stationary Gaussian random excitation. It results in new values of linearization coefficients that are obtained as global averaged values of all local linearization coefficients. Two examples of typical two-degree-of-freedom nonlinear systems under zero-mean stationary Gaussian random excitation are demonstrated. The results show that the accuracy of solutions by the proposed criterion is significantly improved in comparison with the one by the classical equivalent linearization method, especially when the nonlinearity is strong.Dong Anh NguyenX. Hung LeDuc Viet LaC. Thang Nguyen2016-07-06T03:52:33Z2016-07-06T03:53:30Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1790This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/17902016-07-06T03:52:33ZMode shape analysis of a cracked beam and its application for crack detectionViet Khoa Nguyen2016-06-30T09:59:50Z2016-06-30T10:02:12Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1786This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/17862016-06-30T09:59:50ZPartial Stochastic Linearization of a Spherical Pendulum With Coriolis Damping Produced by Radial Spring and DamperThis study considers the stochastic analysis of a spherical pendulum, whose bidirectional vibration is reduced by spring and damper installed in the radial direction between the point mass and the cable. Under sway motion, the centrifugal force results in the radial motion, which in its turn produces the Coriolis force to reduce sway motion. In stochastic analysis and design, the problem is that the Monte Carlo simulation is time-consuming, while the full stochastic linearization totally fails to describe the effectiveness of the spring and damper. We propose the partial linearization applied to the Coriolis damping to overcome the disadvantages of two mentioned methods. Moreover, the proposed technique can give the analytical solution of partial linearized system. A numerical simulation is performed to verify the proposed approach.Duc Viet La2016-05-28T04:00:28Z2016-05-28T04:00:28Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1695This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/16952016-05-28T04:00:28ZNonlinear dynamic response of imperfect symmetric thin S-FGM plate with metal- ceramic-metal layers on elastic foundationDinh Duc Nguyenducnd@vnu.edu.vnHong Cong Pham2016-05-26T15:33:13Z2016-05-26T15:33:44Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1693This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/16932016-05-26T15:33:13ZNonlinear dynamic analysis and vibration of shear deformable piezoelectric FGM double curved shallow shells under damping-thermo-electro-mechanical loadsDinh Duc Nguyenducnd@vnu.edu.vnQuoc Quan TranDinh Luat Vu2016-05-26T15:31:27Z2016-05-26T15:32:03Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1678This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/16782016-05-26T15:31:27ZNonlinear vibration and dynamic response of shear deformable imperfect functionally graded double curved shallow shells resting on elastic foundations in thermal environmentsQuoc Quan TranDinh Duc Nguyenducnd@vnu.edu.vn2016-05-26T15:29:35Z2016-05-26T15:31:11Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1677This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/16772016-05-26T15:29:35ZNonlinear dynamic analysis of Sigmoid functionally graded circular cylindrical shells on elastic foundations using the third order shear deformation theory in thermal environmentsDinh Duc Nguyenducnd@vnu.edu.vnDuc Tuan NgoPhuong TranTrong Dao NguyenTat Dat Ngo2016-05-26T09:01:00Z2016-05-26T09:01:50Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1676This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/16762016-05-26T09:01:00ZThermal stability of eccentrically stiffened FGM plate on elastic foundation based on Reddy’s third-order shear deformation plate theoryDinh Duc Nguyenducnd@vnu.edu.vnHong Cong PhamDinh Quang Vuquangvd2510@gmail.com2016-05-26T08:58:29Z2016-05-26T08:59:13Zhttp://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 Pham2016-05-26T08:50:30Z2016-05-26T08:52:26Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1694This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/16942016-05-26T08:50:30ZNonlinear dynamic analysis and vibration of shear deformable eccentrically stiffened S-FGM cylindrical panels with metal-ceramic-metal layers resting on elastic foundationsQuoc Quan TranPhuong TranDuc Tuan NgoDinh Duc Nguyenducnd@vnu.edu.vn2016-05-26T06:23:52Z2016-05-26T06:25:25Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1699This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/16992016-05-26T06:23:52ZNonlinear vibration of thick FGM plates on elastic foundation subjected to thermal and mechanical loads using the first order shear deformation plate theoryDinh Duc Nguyenducnd@vnu.edu.vnHong Cong Pham2016-05-26T06:21:00Z2016-05-26T06:23:29Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1700This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/17002016-05-26T06:21:00ZNonlinear analysis on flutter of FGM plates using Ilyushin supersonic aerodynamic theoryHong Cong PhamHuy Bich DaoDinh Duc Nguyenducnd@vnu.edu.vn2016-05-26T02:53:43Z2016-05-26T02:55:57Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1692This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/16922016-05-26T02:53:43ZNonlinear dynamic analysis of imperfect FGM double curved thin shallow shells with temperature-dependent properties on elastic foundationDinh Duc Nguyenducnd@vnu.edu.vnQuoc Quan Tran2016-05-26T02:52:16Z2016-05-26T02:53:15Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1702This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/17022016-05-26T02:52:16ZNonlinear stability of thin FGM annular spherical segment in thermal environmentThi Thuy Anh Vuvuanhthuy206@gmail.comHuy Bich DaoDinh Duc Nguyenducnd@vnu.edu.vn2016-05-26T02:51:12Z2016-05-26T02:51:51Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1705This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/17052016-05-26T02:51:12ZThermal stability analysis of eccentrically stiffened Sigmoid FGM plate with metal-ceramic-metal layers based on first-order shear deformation plate theoryDinh Duc Nguyenducnd@vnu.edu.vnHong Cong Pham2016-05-26T02:50:07Z2016-05-26T02:50:55Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1704This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/17042016-05-26T02:50:07ZNonlinear dynamic response of imperfect FGM plates subjected to blast loadDinh Duc Nguyenducnd@vnu.edu.vnDuc Tuan NgoPhuong TranQuoc Quan TranVan Quyen Nguyen2016-05-26T02:39:47Z2016-05-26T02:42:20Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1703This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/17032016-05-26T02:39:47ZResearch on flutter of double curved thin FGM shallow shells on elastic foundations using Ilyushin nonlinear supersonic aerodynamic theoryQuoc Quan TranHuy Bich DaoDinh Duc Nguyenducnd@vnu.edu.vn2016-05-26T02:38:39Z2016-05-26T02:39:30Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1708This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/17082016-05-26T02:38:39ZCrane sway reduction using Coriolis force produced by radial spring and damperDuc Viet La2016-05-26T01:13:31Z2016-05-26T02:36:23Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1696This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/16962016-05-26T01:13:31ZNonlinear buckling analysis of thin FGM annular spherical shells on elastic foundations under external pressure and thermal loadsThi Thuy Anh VuHuy Bich DaoDinh Duc Nguyenducnd@vnu.edu.vn2016-05-25T14:19:21Z2016-05-25T14:20:09Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1701This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/17012016-05-25T14:19:21ZNonlinear analysis on flutter of functional graded cylindrical panels on elastic foundations using the Ilyushin nonlinear supersonic aerodynamic theoryQuoc Quan TranHuy Bich DaoDinh Duc Nguyenducnd@vnu.edu.vn2016-05-25T14:02:55Z2016-05-25T14:06:50Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1707This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/17072016-05-25T14:02:55ZA Cable-Passive Damper System for Sway and Skew Motion Control of a Crane SpreaderDuc Viet LaPark Youngjin2016-05-25T04:03:51Z2016-05-25T04:07:39Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1681This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/16812016-05-25T04:03:51ZNonlinear vibration and dynamic response of imperfect eccentrically stiffened shear deformable sandwich plate with functionally graded material in thermal environmentDinh Duc Nguyenducnd@vnu.edu.vnHong Cong PhamDuc Tuan NgoPhuong TranMinh Anh Vuvuminhanhhp@gmail.comDinh Quang Vuquangvd2510@gmail.com2016-05-25T04:02:33Z2016-05-25T04:03:30Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1680This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/16802016-05-25T04:02:33ZNonlinear mechanical, thermal and thermo-mechanical postbuckling of imperfect eccentrically stiffened thin FGM cylindrical panels on elastic foundationsDinh Duc Nguyenducnd@vnu.edu.vnDuc Tuan NgoQuoc Quan TranVan Quyen NguyenVan Anh Trananhtv0511@gmail.com2016-05-25T04:01:24Z2016-05-25T04:02:19Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1682This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/16822016-05-25T04:01:24ZThe nonlinear stability of axisymmetric FGM annular spherical shells under thermo-mechanical loadThi Thuy Anh VuDinh Duc Nguyenducnd@vnu.edu.vn2016-05-25T03:59:33Z2016-05-25T04:00:59Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1683This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/16832016-05-25T03:59:33ZMechanical and thermal stability of eccentrically stiffened functionally graded conical shell panels resting on elastic foundations and in thermal environmentDinh Duc Nguyenducnd@vnu.edu.vnHong Cong PhamMinh Anh Vuvuminhanhhp@gmail.comDinh Quang Vuquangvd2510@gmail.comPhuong TranDuc Tuan NgoHoa Thinh Nguyen2016-05-25T03:33:45Z2016-05-25T03:35:07Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1686This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/16862016-05-25T03:33:45ZVibration and nonlinear dynamic response of imperfect three-phase polymer nanocomposite panel resting on elastic foundations under hydrodynamic loadsDinh Duc Nguyenducnd@vnu.edu.vnHadavinia HomayounVan Thu PhamQuoc Quan Tran2016-05-25T03:30:06Z2016-05-25T03:30:43Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1684This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/16842016-05-25T03:30:06ZNonlinear response of shear deformable S-FGM shallow spherical shell with ceramic-metal-ceramic layers resting on elastic foundation in thermal environmentThi Thuy Anh VuDinh Duc Nguyenducnd@vnu.edu.vn2016-05-25T03:23:54Z2016-05-25T03:29:42Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1679This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/16792016-05-25T03:23:54ZNonlinear stability of shear deformable eccentrically stiffened functionally graded plates on elastic foundations with temperature-dependent propertiesHong Cong PhamThi Ngoc An PhamDinh Duc Nguyenducnd@vnu.edu.vn2016-05-25T03:02:11Z2016-05-25T03:02:11Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1674This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/16742016-05-25T03:02:11ZStudy of the climate change impacts on water quality in upstream portion of the Cau River Basin, VietnamNgoc Hien HaHuy Hoang BuiThi Huong TranThanh Than TranThi Thu Ha PhamDang Toan TaMinh Son Nguyen2016-05-25T03:01:12Z2016-05-25T03:01:55Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1673This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/16732016-05-25T03:01:12ZTuning of PID Controllers for Overhead Cranes Using Genetic AlgorithmQuang Hoang NguyenVan Khoa VuVan Diep Do2015-11-24T07:48:23Z2015-11-24T07:49:37Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1211This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/12112015-11-24T07:48:23ZNonlinear Thermal Stability of Eccentrically Stiffened Functionally Graded Truncated Conical Shells Surrounded on Elastic FoundationsThis paper studies the thermal stability of an eccentrically stiffened functionally graded truncated conical shells in thermal environment and surrounded on elastic foundations. Both of the FGM shell as well as the stiffeners are deformed under temperature. The formulations are based on the classical shell theory taking into account geometrical nonlinearity, initial geometrical imperfection, temperature-dependent properties and the Lekhnitsky smeared stiffeners technique with Pasternak type elastic foundation. By applying Galerkin method, the closed-form expression for determining the thermal buckling load is obtained. The numerical results show that the critical thermal load in the case of the uniform temperature rise is smaller than one of the linear temperature distribution through the thickness of the shell, and the critical thermal load increases when increasing the coefficient of stiffeners and vice versa. The paper also analyzes and discussed the significant effects of material and geometrical properties, elastic foundations on the thermal buckling capacity of the eccentrically stiffened FGM truncated conical shell in thermal environment. The obtained results are validated by comparing with those in the literature.Dinh Duc Nguyenducnd@vnu.edu.vnHong Cong Pham2015-11-24T07:45:38Z2015-11-24T07:46:49Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1212This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/12122015-11-24T07:45:38ZNonlinear Stability Analysis of Thin FGM Annular Spherical Shells on Elastic Foundations under External Pressure and Thermal LoadsTo increase the thermal resistance of various structural components in high-temperature environments, the present research deals with nonlinear stability analysis of thin annular spherical shells made of functionally graded materials (FGM) on elastic foundations under external pressure and temperature. Material properties are graded in the thickness direction according to a simple power law distribution in terms of the volume fractions of constituents. Classical thin shell theory in terms of the shell deflection and the stress function is used to determine the buckling loads and nonlinear response of the FGM annular spherical shells. Galerkin method is applied to obtain closed – form of load – deflection paths. An analysis is carried out to show the effects of material, geometrical properties, elastic foundations and combination of external pressure and temperature on the nonlinear stability of the annular spherical shells.Thi Thuy Anh Vuvuanhthuy206@gmail.comHuy Bich DaoDinh Duc Nguyenducnd@vnu.edu.vn2015-11-19T08:43:16Z2015-11-19T08:43:55Zhttp://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 Hoang2015-08-27T16:52:41Z2015-08-27T16:52:41Zhttp://eprints.uet.vnu.edu.vn/eprints/id/eprint/1382This item is in the repository with the URL: http://eprints.uet.vnu.edu.vn/eprints/id/eprint/13822015-08-27T16:52:41ZNonlinear Dynamic Analysis and Vibration of Shear Deformable Piezoelectric FGM Double Curved Shallow Shells under Damping-Thermo-Electro-Mechanical LoadsNonlinear dynamic analysis and vibration of imperfect functionally graded materials (FGM) thick double curved shallow shells with piezoelectric actuators on elastic foundations subjected to the combination of electrical, thermal, mechanical and damping loading are investigated in this paper. Material properties of FGM shells are assumed to be temperature dependent and graded in the thickness direction according to a simple power-law distribution in terms of the volume fractions of the constituents. The governing equations are established based on Reddy’s higher order shear deformation theory that includes thermo-piezoelectric effects and are solved by the stress function, the Galerkin method and fourth-order Runge–Kutta method. In numerical results, the effects of geometrical parameters; the material properties; imperfections; elastic foundations; electrical, mechanical, thermal and damping loads on the nonlinear dynamic analysis and nonlinear vibration of the FGM hybrid double curved shallow shells are discussed.Dinh Duc Nguyenducnd@vnu.edu.vnQuoc Quan TranDinh Luat Vu2015-08-05T04:43:30Z2015-08-05T04:43:30Zhttp://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 Pham