The Experts below are selected from a list of 36879 Experts worldwide ranked by ideXlab platform
Brij N Agrawal - One of the best experts on this subject based on the ideXlab platform.
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active position control of a shape memory alloy wire actuated Composite Beam
Smart Materials and Structures, 2000Co-Authors: Gangbing Song, Brian Kelly, Brij N AgrawalAbstract:This paper presents the design and the experimental result of the active position control of a shape memory alloy (SMA) wire actuated Composite Beam. The Composite Beam has a honeycomb structure with SMA wires embedded in one of its face sheets for the active actuation. The potential applications of this experiment include thermo-distortion compensation for precision space structure, stern shape control for submarines, and flap shape control for aeronautical applications. SMA wires are chosen as the actuating elements due to their high recovery stress ({>}500 MPa) and tolerance to high strain (up to 6%). However, SMA wires are inherently nonlinear and pose a challenge for control design. A robust controller is designed and implemented to actively control the tip position of the Composite Beam. The experiment set-up consists of the Composite Beam with embedded SMA wires, a programmable current/voltage amplifier to actuate the SMA wires, an infrared laser range sensor to detect the Beam tip displacement, and a real-time data acquisition and control system. The experimental result demonstrates the effectiveness of the robust control.
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active position control of a shape memory alloy wire actuated Composite Beam
Smart Structures and Materials 1999: Mathematics and Control in Smart Structures, 1999Co-Authors: Gangbing Song, Brian Kelly, Brij N AgrawalAbstract:This paper presents the design and experiment results of active position control of a shape memory alloy (SMA) wires actuated Composite Beam. The Composite Beam is honeycomb structured with shape memory alloy wires embedded in one of its phase sheet for active actuation. The potential applications of this experiment include thermo-distortion compensation for precession space structure, stern shape control for submarines, and flap shape control for aeronautical applications. Shape memory alloy wires are chosen as actuating elements due to their high recovery stress (maybe greater than 700 MPa) and tolerance to high strain (up to 8%). However, shape memory alloy wires are inherently nonlinear and pose a challenge for control design. A robust controller is designed and implemented to active control the tip position of the Composite Beam. The experiment setup consists of the Composite Beam with embedded SMA wires, programmable current/voltage amplifier to actuate the SMA wires, an infrared laser range sensor to detect the Beam tip displacement, and a real-time data acquisition and control system. Experiments demonstrated the effectiveness of the robust control.
K. M. Sathish Kumar - One of the best experts on this subject based on the ideXlab platform.
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Free vibration analysis of smart Composite Beam
Materials Today: Proceedings, 2017Co-Authors: Yashavantha Kumar, G. A. Yashavantha Kumar, M. Sathish Kumar, K. M. Sathish KumarAbstract:The integration of Composite Beam with piezoelectric materials has been under a considerable attention to obtain active lightweight material. Smart materials will control the system in terms of reducing the vibrations amplitude and frequency so as to improve the efficiency of the system. Piezoelectric materials are often used to design smart structures in industrial, medical, military and scientific areas. The aim of the present study is to study the free vibration behaviour of a smart Composite Beam structure. Smart Beam consists of Composite Beam modelled in cantilever configuration with PZT patches. The modal analysis of the smart cantilever Beam was performed using the ANSYS software to reveal the fundamental modal frequencies and modal shapes. It can be inferred that the Modal analysis performed is usefull for applications in structural health monitoring of the smart Composite structures. The changes in the mode shapes are used as an indicator to ascertain the damage to the smart composte Beam structure.
Gangbing Song - One of the best experts on this subject based on the ideXlab platform.
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active vibration damping of Composite Beam using smart sensors and actuators
Journal of Aerospace Engineering, 2002Co-Authors: Gangbing Song, Pizhong Qiao, Wieslaw K. BiniendaAbstract:This paper discusses active vibration control of an E-glass/epoxy-laminated Composite Beam using smart sensors and actua- tors. The smart sensors and actuators used in this study are piezoelectric ceramic patches. The Composite Beam is in a cantilevered configuration. Both theoretical and numerical ~finite-element analysis! studies of the laminated Composite Beam are conducted to reveal the Beam's fundamental modal frequencies and modal shapes. The results based on the theoretical predication and numerical simulation are then compared with those from experimental modal testing, and a good correlation is obtained. Utilizing results from the model analysis and experimental modal testing, two control algorithms, namely, positive position feedback control and strain rate feedback control, are designed. Both single-mode vibration suppression and multimode vibration suppression are studied. An experimental appa- ratus has been developed to implement the control algorithms. The apparatus consists of a voltage amplifier and a data acquisition and real-time control system, in addition to the Composite Beam with bonded piezoelectric ceramic sensors and actuators. Experiments show that the proposed controllers can achieve active vibration damping of the Composite Beam.
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active position control of a shape memory alloy wire actuated Composite Beam
Smart Materials and Structures, 2000Co-Authors: Gangbing Song, Brian Kelly, Brij N AgrawalAbstract:This paper presents the design and the experimental result of the active position control of a shape memory alloy (SMA) wire actuated Composite Beam. The Composite Beam has a honeycomb structure with SMA wires embedded in one of its face sheets for the active actuation. The potential applications of this experiment include thermo-distortion compensation for precision space structure, stern shape control for submarines, and flap shape control for aeronautical applications. SMA wires are chosen as the actuating elements due to their high recovery stress ({>}500 MPa) and tolerance to high strain (up to 6%). However, SMA wires are inherently nonlinear and pose a challenge for control design. A robust controller is designed and implemented to actively control the tip position of the Composite Beam. The experiment set-up consists of the Composite Beam with embedded SMA wires, a programmable current/voltage amplifier to actuate the SMA wires, an infrared laser range sensor to detect the Beam tip displacement, and a real-time data acquisition and control system. The experimental result demonstrates the effectiveness of the robust control.
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active position control of a shape memory alloy wire actuated Composite Beam
Smart Structures and Materials 1999: Mathematics and Control in Smart Structures, 1999Co-Authors: Gangbing Song, Brian Kelly, Brij N AgrawalAbstract:This paper presents the design and experiment results of active position control of a shape memory alloy (SMA) wires actuated Composite Beam. The Composite Beam is honeycomb structured with shape memory alloy wires embedded in one of its phase sheet for active actuation. The potential applications of this experiment include thermo-distortion compensation for precession space structure, stern shape control for submarines, and flap shape control for aeronautical applications. Shape memory alloy wires are chosen as actuating elements due to their high recovery stress (maybe greater than 700 MPa) and tolerance to high strain (up to 8%). However, shape memory alloy wires are inherently nonlinear and pose a challenge for control design. A robust controller is designed and implemented to active control the tip position of the Composite Beam. The experiment setup consists of the Composite Beam with embedded SMA wires, programmable current/voltage amplifier to actuate the SMA wires, an infrared laser range sensor to detect the Beam tip displacement, and a real-time data acquisition and control system. Experiments demonstrated the effectiveness of the robust control.
Yashavantha Kumar - One of the best experts on this subject based on the ideXlab platform.
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Free vibration analysis of smart Composite Beam
Materials Today: Proceedings, 2017Co-Authors: Yashavantha Kumar, G. A. Yashavantha Kumar, M. Sathish Kumar, K. M. Sathish KumarAbstract:The integration of Composite Beam with piezoelectric materials has been under a considerable attention to obtain active lightweight material. Smart materials will control the system in terms of reducing the vibrations amplitude and frequency so as to improve the efficiency of the system. Piezoelectric materials are often used to design smart structures in industrial, medical, military and scientific areas. The aim of the present study is to study the free vibration behaviour of a smart Composite Beam structure. Smart Beam consists of Composite Beam modelled in cantilever configuration with PZT patches. The modal analysis of the smart cantilever Beam was performed using the ANSYS software to reveal the fundamental modal frequencies and modal shapes. It can be inferred that the Modal analysis performed is usefull for applications in structural health monitoring of the smart Composite structures. The changes in the mode shapes are used as an indicator to ascertain the damage to the smart composte Beam structure.
Ulf Arne Girhammar - One of the best experts on this subject based on the ideXlab platform.
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A Comparison of Exact and Approximate Analyses of Partially Interacting Composite Beam-Columns
Proceedings of the Fifteenth International Conference on Civil Structural and Environmental Engineering Computing, 2016Co-Authors: Staffan Grundberg, Ulf Arne GirhammarAbstract:Solutions of the static Euler-Bernoulli equations of Composite Beam-columns with interlayer slip have been compared with an approximate theory. The inter-layer force was taken to be proportional to ...
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Variationally-based theories for buckling of partial Composite Beam-columns including shear and axial effects
Engineering Structures, 2011Co-Authors: Noël Challamel, Ulf Arne GirhammarAbstract:This paper is focused on elastic stability problems of partial Composite columns: the conditions for the axial load not to introduce any pre-bending effects in Composite columns; the equivalence, similarities and differences between different sandwich and partial Composite Beam theories with and without the effect of shear, with and without the effect of axial extensibility, and also the effect of eccentric axial load application. The basic modelling of the Composite Beam-column uses the Euler-Bernoulli Beam theory and a linear constitutive law for the slip. In the analysis of this reference model, a variational formulation is used in order to derive relevant boundary conditions. The specific loading associated with no pre-bending effects before buckling is geometrically characterized, leading to analytical buckling loads of the partial Composite column. The equivalence between the Hoff theory for sandwich Beam-columns, the Composite action theory for Beam-columns with interlayer slip and the corresponding Bickford-Reddy theory, is shown from the stability point of view. Special loading configurations including eccentric axial load applications and axial loading only on one of the sub-elements of the Composite Beam-column are investigated and the similarity of the behaviour to that of imperfect ordinary Beam-columns is demonstrated. The effect of axial extensibility on kinematical relationships (according to the Reissner theory), is analytically quantified and compared to the classical solution of the problem. Finally, the effect of incorporating shear in the analysis of Composite members using the Timoshenko theory is evaluated. By using a variational formulation, the buckling behaviour of partial Composite columns is analysed with respect to both the Engesser and the Haringx theory. A simplified uniform shear theory (assuming equal shear deformations in each sub-element) for the partial Composite Beam-column is first presented, and then a refined differential shear theory (assuming individual shear deformations in each sub-element) is evaluated. The paper concludes with a discussion on this shear effect, the differences between the shear theories presented and when the shear effect can be neglected.
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Composite Beam columns with interlayer slip exact analysis
Journal of Structural Engineering-asce, 1993Co-Authors: Ulf Arne Girhammar, Vijaya K A GopuAbstract:Exact first‐ and second‐order analyses for Composite Beam‐columns with partial interaction and subjected to transverse and axial loading are presented. General closed‐form solutions for the displacement functions and the various actions in the Composite element are presented for the first‐ and second‐order cases. In this paper, the axial loads acting on the Composite elements are assumed to be proportioned in accordance with their relative axial stiffnesses so that their resultant acts at the centroid of the transformed cross‐sectional area of the fully Composite member. Resultant axial loads active at the centroid ensure that, in the first‐order analysis, the Composite elements are subjected to uniform axial strain through the depth of the member and that no bending is induced by the resultant axial load. The analysis procedures are applied to simply supported Beam‐columns subjected to an axial force and a uniformly distributed transverse load to obtain closed‐form solutions for the internal actions and ...
