The Experts below are selected from a list of 67176 Experts worldwide ranked by ideXlab platform
Seungbok Choi - One of the best experts on this subject based on the ideXlab platform.
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active Vibration Control of ring stiffened cylindrical shell structure using macro fiber composite actuators
Journal of Nanoscience and Nanotechnology, 2014Co-Authors: Jungwoo Sohn, Juncheol Jeon, Seungbok ChoiAbstract:Vibration Control performance of the ring-stiffened cylindrical shell structure is experimentally evaluated in this work. In order to achieve high Control performance, advanced flexible piezoelectric actuator whose commercial name is Macro-Fiber Composite (MFC) is adapted to the shell structure. Governing equation is derived by finite element method and dynamic characteristics are investigated from the modal analysis results. Ring-stiffened cylindrical shell structure is then manufactured and modal test is conducted to verify modal analysis results. An optimal Controller is designed and experimentally realized to the proposed shell structure system. Vibration Control performance is experimentally evaluated in time domain and verified by simulated Control results.
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Vibration Control of flexible structures using semi active mount experimental investigation
2012Co-Authors: Seungbok Choi, Sung Hoon Ha, Juncheol JeonAbstract:In many dynamic systems such as robot and aerospace areas, flexible structures have been extremely employed to satisfy various requirements for large scale, light weight and high speed in dynamic motion. However, these flexible structures are readily susceptible to the internal/external disturbances (or excitations). Therefore, Vibration Control schemes should be exerted to achieve high performance and stability of flexible structure systems. Recently, in order to successfully achieve Vibration Control for flexible structures smart materials such as piezoelectric materials [1-2], shape memory alloys [3-4], electrorheological (ER) fluids [5-6] and magnetorheological (MR) fluids [7] are being widely utilized. Among these smart materials, ER or MR fluid exhibits reversible changes in material characteristics when sub‐ jected to electric or magnetic field. The Vibration Control of flexible structures using the smart ER or MR fluid can be achieved from two different methods. The first approach is to replace conventional viscoelastic materials by the ER or MR fluid. This method is very effec‐ tive for shape Control of flexible structures such as plate [5]. The second approach is to de‐ vise dampers or mounts and apply to Vibration Control of the flexible structures. This method is very useful to isolate Vibration of large structural systems subjected to external excitations [6-7]. In this work, a new type of MR mount is proposed and applied to Vibration Control of the flexible structures.
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Vibration Control of smart hull structure with optimally placed piezoelectric composite actuators
International Journal of Mechanical Sciences, 2011Co-Authors: Jungwoo Sohn, Seungbok Choi, Heung Soo KimAbstract:Abstract Active Vibration Control to suppress structural Vibration of the smart hull structure was investigated based on optimized actuator configurations. Advanced anisotropic piezoelectric composite actuator, Macro-Fiber Composite (MFC), was used for the Vibration Control. Governing equations of motion of the smart hull structure including MFC actuators were obtained using the Donnell–Mushtari shell theory and Lagrange's equation. The Rayleigh–Ritz method was used to obtain the dynamic characteristics of the smart hull structure. Experimental modal tests were conducted to verify the proposed mathematical model. In order to achieve high Control performance, optimal locations and directions of the MFC actuators were determined by genetic algorithm. Optimal Control algorithm was then synthesized to suppress structural Vibration of the proposed smart hull structure and experimentally implemented to the system. Active Vibration Control performances were evaluated under various modes excitations. Vibration tests revealed that optimal configurations of MFC actuators improved the Control performance of the smart hull structure in case of the limited number of actuators available.
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Vibration Control of smart hull structure with optimally placed piezoelectric composite actuators
International Journal of Mechanical Sciences, 2011Co-Authors: Jungwoo Sohn, Seungbok ChoiAbstract:Abstract Active Vibration Control to suppress structural Vibration of the smart hull structure was investigated based on optimized actuator configurations. Advanced anisotropic piezoelectric composite actuator, Macro-Fiber Composite (MFC), was used for the Vibration Control. Governing equations of motion of the smart hull structure including MFC actuators were obtained using the Donnell–Mushtari shell theory and Lagrange's equation. The Rayleigh–Ritz method was used to obtain the dynamic characteristics of the smart hull structure. Experimental modal tests were conducted to verify the proposed mathematical model. In order to achieve high Control performance, optimal locations and directions of the MFC actuators were determined by genetic algorithm. Optimal Control algorithm was then synthesized to suppress structural Vibration of the proposed smart hull structure and experimentally implemented to the system. Active Vibration Control performances were evaluated under various modes excitations. Vibration tests revealed that optimal configurations of MFC actuators improved the Control performance of the smart hull structure in case of the limited number of actuators available.
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active Vibration Control of smart hull structure using piezoelectric composite actuators
Smart Materials and Structures, 2009Co-Authors: Jungwoo Sohn, Seungbok Choi, Chulhee LeeAbstract:In this paper, active Vibration Control performance of the smart hull structure with macro-fiber composite (MFC) is evaluated. MFC is an advanced piezoelectric composite which has great flexibility and increased actuating performance compared to a monolithic piezoelectric ceramic patch. The governing equations of motion of the hull structure with MFC actuators are derived based on the classical Donnell–Mushtari shell theory. The actuating model for the interaction between hull structure and MFC is included in the governing equations. Subsequently, modal characteristics are investigated and compared with the results obtained from experiment. The governing equations of the Vibration Control system are then established and expressed in the state space form. A linear quadratic Gaussian (LQG) Control algorithm is designed in order to effectively and actively Control the imposed Vibration. The Controller is experimentally realized and Vibration Control performances are evaluated.
Heung Soo Kim - One of the best experts on this subject based on the ideXlab platform.
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Analysis of sensor-debonding failure in active Vibration Control of smart composite plate:
Journal of Intelligent Material Systems and Structures, 2017Co-Authors: Asif Khan, Hyun Sung Lee, Heung Soo KimAbstract:In this article, the effect of a sensor-debonding failure on the active Vibration Control of a smart composite plate is investigated numerically. A mathematical model of the smart structure with a ...
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Vibration Control of smart hull structure with optimally placed piezoelectric composite actuators
International Journal of Mechanical Sciences, 2011Co-Authors: Jungwoo Sohn, Seungbok Choi, Heung Soo KimAbstract:Abstract Active Vibration Control to suppress structural Vibration of the smart hull structure was investigated based on optimized actuator configurations. Advanced anisotropic piezoelectric composite actuator, Macro-Fiber Composite (MFC), was used for the Vibration Control. Governing equations of motion of the smart hull structure including MFC actuators were obtained using the Donnell–Mushtari shell theory and Lagrange's equation. The Rayleigh–Ritz method was used to obtain the dynamic characteristics of the smart hull structure. Experimental modal tests were conducted to verify the proposed mathematical model. In order to achieve high Control performance, optimal locations and directions of the MFC actuators were determined by genetic algorithm. Optimal Control algorithm was then synthesized to suppress structural Vibration of the proposed smart hull structure and experimentally implemented to the system. Active Vibration Control performances were evaluated under various modes excitations. Vibration tests revealed that optimal configurations of MFC actuators improved the Control performance of the smart hull structure in case of the limited number of actuators available.
Yufei Liu - One of the best experts on this subject based on the ideXlab platform.
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optimal placement and active Vibration Control for piezoelectric smart flexible manipulators using modal h2 norm
Journal of Intelligent Material Systems and Structures, 2018Co-Authors: Xuefeng Yang, Yuqiao Wang, Yufei LiuAbstract:The optimal placement and active Vibration Control for piezoelectric smart single flexible manipulator are investigated in this study. Based on the assumed mode method and Hamilton’s principle, the...
Jungwoo Sohn - One of the best experts on this subject based on the ideXlab platform.
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active Vibration Control of ring stiffened cylindrical shell structure using macro fiber composite actuators
Journal of Nanoscience and Nanotechnology, 2014Co-Authors: Jungwoo Sohn, Juncheol Jeon, Seungbok ChoiAbstract:Vibration Control performance of the ring-stiffened cylindrical shell structure is experimentally evaluated in this work. In order to achieve high Control performance, advanced flexible piezoelectric actuator whose commercial name is Macro-Fiber Composite (MFC) is adapted to the shell structure. Governing equation is derived by finite element method and dynamic characteristics are investigated from the modal analysis results. Ring-stiffened cylindrical shell structure is then manufactured and modal test is conducted to verify modal analysis results. An optimal Controller is designed and experimentally realized to the proposed shell structure system. Vibration Control performance is experimentally evaluated in time domain and verified by simulated Control results.
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Vibration Control of smart hull structure with optimally placed piezoelectric composite actuators
International Journal of Mechanical Sciences, 2011Co-Authors: Jungwoo Sohn, Seungbok Choi, Heung Soo KimAbstract:Abstract Active Vibration Control to suppress structural Vibration of the smart hull structure was investigated based on optimized actuator configurations. Advanced anisotropic piezoelectric composite actuator, Macro-Fiber Composite (MFC), was used for the Vibration Control. Governing equations of motion of the smart hull structure including MFC actuators were obtained using the Donnell–Mushtari shell theory and Lagrange's equation. The Rayleigh–Ritz method was used to obtain the dynamic characteristics of the smart hull structure. Experimental modal tests were conducted to verify the proposed mathematical model. In order to achieve high Control performance, optimal locations and directions of the MFC actuators were determined by genetic algorithm. Optimal Control algorithm was then synthesized to suppress structural Vibration of the proposed smart hull structure and experimentally implemented to the system. Active Vibration Control performances were evaluated under various modes excitations. Vibration tests revealed that optimal configurations of MFC actuators improved the Control performance of the smart hull structure in case of the limited number of actuators available.
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Vibration Control of smart hull structure with optimally placed piezoelectric composite actuators
International Journal of Mechanical Sciences, 2011Co-Authors: Jungwoo Sohn, Seungbok ChoiAbstract:Abstract Active Vibration Control to suppress structural Vibration of the smart hull structure was investigated based on optimized actuator configurations. Advanced anisotropic piezoelectric composite actuator, Macro-Fiber Composite (MFC), was used for the Vibration Control. Governing equations of motion of the smart hull structure including MFC actuators were obtained using the Donnell–Mushtari shell theory and Lagrange's equation. The Rayleigh–Ritz method was used to obtain the dynamic characteristics of the smart hull structure. Experimental modal tests were conducted to verify the proposed mathematical model. In order to achieve high Control performance, optimal locations and directions of the MFC actuators were determined by genetic algorithm. Optimal Control algorithm was then synthesized to suppress structural Vibration of the proposed smart hull structure and experimentally implemented to the system. Active Vibration Control performances were evaluated under various modes excitations. Vibration tests revealed that optimal configurations of MFC actuators improved the Control performance of the smart hull structure in case of the limited number of actuators available.
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active Vibration Control of smart hull structure using piezoelectric composite actuators
Smart Materials and Structures, 2009Co-Authors: Jungwoo Sohn, Seungbok Choi, Chulhee LeeAbstract:In this paper, active Vibration Control performance of the smart hull structure with macro-fiber composite (MFC) is evaluated. MFC is an advanced piezoelectric composite which has great flexibility and increased actuating performance compared to a monolithic piezoelectric ceramic patch. The governing equations of motion of the hull structure with MFC actuators are derived based on the classical Donnell–Mushtari shell theory. The actuating model for the interaction between hull structure and MFC is included in the governing equations. Subsequently, modal characteristics are investigated and compared with the results obtained from experiment. The governing equations of the Vibration Control system are then established and expressed in the state space form. A linear quadratic Gaussian (LQG) Control algorithm is designed in order to effectively and actively Control the imposed Vibration. The Controller is experimentally realized and Vibration Control performances are evaluated.
S T Quek - One of the best experts on this subject based on the ideXlab platform.
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topology optimization of piezoelectric sensors actuators for torsional Vibration Control of composite plates
Smart Materials and Structures, 2006Co-Authors: S. Y. Wang, S T QuekAbstract:Torsional Vibration Control can be crucial for applications of smart materials and structures. In this paper, the problem of topology optimization of collocated piezoelectric sensor/actuator (S/A) pairs for torsional Vibration Control of a laminated composite plate is directly addressed. Both isotropic and anisotropic PZT S/A pairs are considered and it is highlighted that the torsional Vibration can be more effectively damped out by employing the topological optimal design of the S/A pairs than by using the conventional designs. To implement this topology optimization, a genetic algorithm (GA) based on a bit-array representation method is presented and a finite element (FE) simulation model based on the first-order shear theory and an output feedback Control law is adopted. Numerical experiments are used to verify the present algorithm and show that the present optimal topology design can achieve significantly better active damping effect than the one using a continuously distributed PZT S/A pair, which was often adopted by many other researchers. Together with the progress in laser cutting and micromachining techniques, topology optimization of piezoelectric sensors and/or actuators would be promising in active Vibration Control of smart structures.
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Vibration Control of smart piezoelectric composite plates
Smart Materials and Structures, 2001Co-Authors: Shengyin Wang, S T Quek, Kok Keng AngAbstract:This study on the Vibration Control of smart piezoelectric composite plates investigates the effect of the stretching-bending coupling of the piezoelectric sensor/actuator pairs on the system stability of smart composite plates. Based on first-order shear theory and consistent methodology, a smart isoparametric finite element is formulated and the classical negative velocity feedback Control method is adopted for the active Vibration Control analysis of smart composite plates with bonded or embedded distributed piezoelectric sensors and actuators. It is shown mathematically and demonstrated numerically that generally the coupling effect tends to result in system instability unless the sensor/actuator pairs are collocated or the plate simply supported. The result of this study can be used to aid the placement of piezoelectric sensor/actuator pairs of smart composite plates as well as for robust Controller design.
