The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Hui-shen Shen - One of the best experts on this subject based on the ideXlab platform.
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Nonlinear Dynamics of Temperature-Dependent FG-GRC Laminated Beams Resting on Visco-Pasternak Foundations
International Journal of Structural Stability and Dynamics, 2019Co-Authors: Yin Fan, Yang Xiang, Hui-shen ShenAbstract:This paper studies the nonlinear dynamic responses of graphene-reinforced composite (GRC) Beams in a thermal environment. It is assumed that a Laminated Beam rests on a Pasternak foundation with vi...
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Nonlinear Vibration of Thermally Postbuckled FG-GRC Laminated Beams Resting on Elastic Foundations
International Journal of Structural Stability and Dynamics, 2019Co-Authors: Hui-shen Shen, Yang Xiang, Yin FanAbstract:Investigated herein are the small- and large-amplitude vibrations of a thermally postbuckled graphene-reinforced composite (GRC) Laminated Beam supported by an elastic foundation. The piecewise GRC...
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Nonlinear Vibration of Thermally Postbuckled FG-GRC Laminated Beams Resting on Elastic Foundations
International Journal of Structural Stability and Dynamics, 2019Co-Authors: Hui-shen Shen, Yang Xiang, Yin FanAbstract:Investigated herein are the small- and large-amplitude vibrations of a thermally postbuckled graphene-reinforced composite (GRC) Laminated Beam supported by an elastic foundation. The piecewise GRC layers are arranged in a functionally graded (FG) pattern along the thickness direction of the Beam. The temperature-dependent material properties of functionally graded graphene-reinforced composites (FG-GRCs) are estimated through the extended Halpin–Tsai micromechanical model. The nonlinear governing differential equations are derived from the higher-order shear deformation Beam theory and the von Kármán-type strain–displacement relationships. The thermal effect, the Beam–foundation interaction and the initial deflection caused by thermal postbuckling are also included. A two-step perturbation approach is applied to determine the thermal postbuckling equilibrium paths as well as the nonlinear vibration solutions for the FG-GRC Laminated Beams. Results are presented to demonstrate the nonlinear vibration responses of thermally postbuckled FG-GRC Laminated Beams under a uniform temperature field. The effects of the FG reinforcement patterns and the foundation stiffness on the nonlinear vibration responses of FG-GRC Laminated Beams are examined and discussed.
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Nonlinear analysis of functionally graded fiber reinforced composite Laminated Beams in hygrothermal environments, Part II: Numerical results
Composite Structures, 2015Co-Authors: Hui-shen ShenAbstract:In this part, the extensive parametric studies performed are reported and numerical results are presented for the nonlinear vibration, nonlinear bending and thermal postbuckling of uniformly distributed and functionally graded fiber reinforced cross-ply and angle-ply Laminated Beams resting on Pasternak elastic foundations under different sets of hygrothermal environmental conditions. The numerical results reveal that a functionally graded reinforcement has a significant effect on the nonlinear vibration characteristics, nonlinear bending behaviors, and thermal postbuckling behaviors of fiber reinforced composite (FRC) Laminated Beams. The results show that the temperature/moisture variation has a moderately effect on the natural frequencies of the FRC Laminated Beam, but only has a small effect on the nonlinear to linear frequency ratios of the same Beam. In contrast, it has a significant effect on the nonlinear bending load–deflection curves of the FRC Laminated Beam. The results confirm that the thermal postbuckling equilibrium path of mid-plane unsymmetric FG-FRC Laminated Beams with immovable simply supported end conditions is no longer the bifurcation type.
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Nonlinear vibration of functionally graded fiber reinforced composite Laminated Beams with piezoelectric fiber reinforced composite actuators in thermal environments
Engineering Structures, 2015Co-Authors: Hui-shen Shen, De-qing YangAbstract:Abstract A large amplitude flexural vibration of a hybrid Laminated Beam resting on an elastic foundation in thermal environments is investigated. The hybrid Laminated Beam is consists of fiber reinforced composite (FRC) layers and piezoelectric fiber reinforced composite (PFRC) actuators. The fiber reinforcements are assumed to be distributed either uniformly (UD) or functionally graded (FG) of piece-wise type along the thickness of the Beam. The motion equations are based on a higher order shear deformation theory and von Karman strain displacement relationships. The Beam-foundation interaction and thermo-piezoelectric effects are also included. The material properties of both FRCs and PFRCs are estimated through a micromechanical model and are assumed to be temperature dependent. A two-step perturbation approach is employed to determine the nonlinear to linear frequency ratios of hybrid Laminated Beams. Detailed parametric studies are carried out to investigate effects of material property gradient, temperature variation, applied voltage, stacking sequence as well as the foundation stiffness on the linear and nonlinear vibration characteristics of the hybrid Laminated Beams.
Shengping Shen - One of the best experts on this subject based on the ideXlab platform.
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Flexoelectric energy harvesters based on Timoshenko Laminated Beam theory
Journal of Intelligent Material Systems and Structures, 2017Co-Authors: Xu Liang, Runzhi Zhang, Shengping ShenAbstract:Different from piezoelectricity which is restricted to certain materials, flexoelectricity is a universal electromechanical coupling in all dielectrics. In this work, mechanical energy harvester models were developed based on Timoshenko Laminated Beam theory, in which the flexoelectric and piezoelectric mechanisms were discussed. For a three-layered energy harvester in parallel configuration, the mechanical vibration energy can be converted into electrical energy due to flexoelectricity, and for the three-layered energy harvester in series configuration, the energy conversion is enhanced by the flexoelectricity. Resonance frequency shifts were observed in the calculations due to flexoelectricity and external circuit resistance. It is found that the electromechanical coupling displayed from the electrical responses versus resonance frequency and resistance. The energy conversion for the three-layered energy harvester system was found to be increased with the decrease in the Laminated Beam thickness. The energy conversion calculated for different numbers of layers also indicates that Laminated energy harvester systems excel single-layered energy harvesters. This work therefore might help in designing flexoelectricity-based energy harvesters.
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flexoelectric energy harvesters based on timoshenko Laminated Beam theory
Journal of Intelligent Material Systems and Structures, 2017Co-Authors: Xu Liang, Runzhi Zhang, Shengping ShenAbstract:Different from piezoelectricity which is restricted to certain materials, flexoelectricity is a universal electromechanical coupling in all dielectrics. In this work, mechanical energy harvester mo...
Wanji Chen - One of the best experts on this subject based on the ideXlab platform.
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a model of composite Laminated Beam based on the global local theory and new modified couple stress theory
Composite Structures, 2013Co-Authors: Wanji ChenAbstract:Abstract In this paper, a model of composite Laminated Beam based on the global–local theory for new modified couple-stress theory is developed. For the modified couple-stress theory, an anisotropic constitutive relation is suggested. There is only one microlength-scale parameter in each ply of the composite Laminated Beam. The Reddy Beam model of global–local higher-order theory proposed by Chen and Wu (2005) [1] , which satisfies free surface conditions and the geometric and stresses continuity conditions at interfaces, and is adopted to formulate this model. On the model of Laminated Beam of modified couple stress theory, the transverse shear stress with scale effect is presented for the first time. Numerical results show that the proposed Beam model can capture the scale effect at interfaces of the microstructure of the composite Laminated Beam.
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A model of composite Laminated Beam based on the global–local theory and new modified couple-stress theory
Composite Structures, 2013Co-Authors: Wanji ChenAbstract:Abstract In this paper, a model of composite Laminated Beam based on the global–local theory for new modified couple-stress theory is developed. For the modified couple-stress theory, an anisotropic constitutive relation is suggested. There is only one microlength-scale parameter in each ply of the composite Laminated Beam. The Reddy Beam model of global–local higher-order theory proposed by Chen and Wu (2005) [1] , which satisfies free surface conditions and the geometric and stresses continuity conditions at interfaces, and is adopted to formulate this model. On the model of Laminated Beam of modified couple stress theory, the transverse shear stress with scale effect is presented for the first time. Numerical results show that the proposed Beam model can capture the scale effect at interfaces of the microstructure of the composite Laminated Beam.
Xuan-hoang Nguyen - One of the best experts on this subject based on the ideXlab platform.
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Optimum design of thin-walled composite Beams for flexural–torsional buckling problem
Composite Structures, 2015Co-Authors: Xuan-hoang NguyenAbstract:Abstract The objective of this research is to present formulation and solution methodology for optimum design of thin-walled composite Beams. The geometric parameters and the fiber orientation of Beams are treated as design variables simultaneously. The objective function of optimization problem is to maximize the critical flexural–torsional buckling loads of axially loaded Beams which are calculated by a displacement-based one-dimensional finite element model. The analysis of Beam is based on the classical Laminated Beam theory and applied for arbitrary laminate stacking sequence configuration. A micro genetic algorithm (micro-GA) is employed as a tool for obtaining optimal solutions. It offers faster convergence to the optimal results with smaller number of populations than the conventional GA. Several types of lay-up schemes as well as different Beam lengths and boundary conditions are investigated in optimization problems of I-section composite Beams. Obtained numerical results show more sensitivity of geometric parameters on the critical flexural–torsional buckling loads than that of fiber angle.
Igor Pesic - One of the best experts on this subject based on the ideXlab platform.
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global buckling analysis model for thin walled composite Laminated Beam type structures
Composite Structures, 2014Co-Authors: Domagoj Lanc, Goran Turkalj, Igor PesicAbstract:This paper presents a Beam finite element model for non-linear global buckling analysis of composite Laminated Beam type structures. To perform the non-linear stability analysis, the framework of updated Lagrangian incremental formulation is used. The non-linear displacement field of thin-walled cross-section is adopted in order to insure the geometric potential of semitangential type for both the internal torsion and bending moments. The cross-section mid-line contour is assumed to remain not deformed in its own plane and the shear strains of middle surface are neglected. The laminates are modeled on the basis of classical lamination theory. In order to illustrate the application of the proposed formulation, several numerical examples are presented. For validation purposes, the obtained results are compared with results reported in the literature and the ones obtained with shell finite elements by Nastran.
