The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
M C Ray - One of the best experts on this subject based on the ideXlab platform.
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active control of doubly curved laminated composite shells using elliptical smart constrained layer Damping Treatment
Thin-walled Structures, 2019Co-Authors: S R Sahoo, M C RayAbstract:Abstract In this paper, performance of the smart constrained layer Damping (SCLD) Treatment with elliptical geometrical plan form is investigated for controlling the vibrations of various types of doubly curved composite shells. The SCLD Treatment is composed of a viscoelastic layer and an advanced constraining piezoelectric composite (PZC) layer attached at the top surface of the composite shell. A mesh free (MF) model of the smart composite shell has been developed based on the element free Galerkin approach to study its dynamic behaviour within the framework of a mixed layerwise displacement field theory considering transverse extensibility. Spherical, paraboloid and hyperboloid type composite shells with antisymmetric/symmetric cross-ply as well as general angle-ply lamination sequences are considered for the analysis. The numerical results demonstrated that the elliptical SCLD patches are more efficient in attenuating the vibration of the spherical and paraboloid laminated shells while the regular rectangular/square plan form patches are effective for the hyperboloid shells. The numerical results also indicate that the elliptical patches are having higher performance index in enhancing the active Damping characteristics of the composite shells. Investigations are also carried out to analyze the effect of the variation in orientation of the piezoelectric fibers in the active PZC layers in attenuating the vibration of shells.
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active control of laminated composite plates using elliptical smart constrained layer Damping Treatment
Composite Structures, 2019Co-Authors: S R Sahoo, M C RayAbstract:Abstract In this article, performance of the elliptical patches of smart constrained layer Damping (SCLD) Treatment is investigated for controlling vibrations of smart laminated composite plates. A three dimensional mesh free model (MFM) has been implemented for the first time based on the element free Galerkin (EFG) method and layer wise displacement theory for studying the dynamic behavior of the composite plates integrated with the SCLD Treatments. Symmetric/antisymmetric cross-ply and general angle-ply laminates are considered for the substrate of the smart composite plates. Circular and regular rectangular type patches are also considered for the analysis. It is observed that the elliptical SCLD patches are more efficient in attenuating the amplitude of vibration in the laminated composite plates as compared to the circular and square type patches. The results from numerical analysis also reveal that the elliptical patches have the maximum performance index followed by the circular and the square type SCLD patches in enhancing the active Damping characteristics of smart composite plates. The performance of the elliptical patch is sensitive to the piezoelectric fiber orientation angle and becomes maximum if the piezoelectric fiber orientation is vertical irrespective of the types of SCLD patches considered as well as the lamination sequence.
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three dimensional fractional derivative model of smart constrained layer Damping Treatment for composite plates
Composite Structures, 2016Co-Authors: Priyankar Datta, M C RayAbstract:Abstract This paper deals with the finite element analysis of active constrained layer Damping (ACLD) of laminated composite plates using fractional order derivative constitutive relations for viscoelastic material. The constraining layer of the ACLD Treatment is composed of the vertically/obliquely reinforced 1–3 piezoelectric composites (PZCs). The novelty of the present analysis is that the three dimensional fractional derivative model (FDM) of the constrained viscoelastic layer has been derived in time domain. A three-dimensional finite element model has been developed based on the FDM of the viscoelastic layer. Thin laminated plates with various boundary conditions and stacking sequences are emphatically analyzed to investigate the effectiveness of the three-dimensional FDM for both the passive and active control authority of the ACLD patch.
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active structural acoustic control of laminated cylindrical panels using smart Damping Treatment
International Journal of Mechanical Sciences, 2007Co-Authors: M C Ray, R BalajiAbstract:Abstract In this paper, the performance of active constrained layer Damping (ACLD) Treatment for active structural–acoustic control of a vibrating thin laminated cylindrical panel has been investigated. The constraining layer of the ACLD Treatment has been considered to be made of piezoelectric fiber-reinforced composite (PFRC) material. A finite element model has been developed for the laminated panels integrated with the patches of ACLD Treatment to describe the coupled structural–acoustic behavior of the panels enclosing an acoustic cavity. Both velocity and pressure rate feedback controls have been implemented to activate the patches. Symmetric and antisymmetric cross-ply and antisymmetric angle-ply panels have been considered for evaluating the numerical results. Emphasis has also been placed on investigating the effect of the piezoelectric fiber orientation in the PFRC layer and the shallowness angle of the cylindrical panels on the performance of the patches.
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performance of smart Damping Treatment using piezoelectric fiber reinforced composites
AIAA Journal, 2005Co-Authors: M C Ray, Nilanjan MallikAbstract:This study deals with the active constrained layer Damping (ACLD) of laminated composite plates to demonstrate the performance of piezoelectric fiber-reinforced composite (PFRC) layer as the constraining layer of ACLD Treatment. A finite element model is developed for the smart composite plates integrated with the patches of ACLD Treatment. The performance of the constraining PFRC layer has been investigated for active Damping of thin symmetric and antisymmetric crossply and antisymmetric angle-ply laminated composite plates. The main concern of this study has been focused on investigating the significant effect of variation of piezoelectric fiber orientation in the PFRC layer on enhancing the Damping characteristics of the laminated substrate plates, and the fiber angle in the PFRC layer for which the control authority of the patches becomes maximum has been determined.
I Y Shen - One of the best experts on this subject based on the ideXlab platform.
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Experimental and Finite Element Analysis of Stand-Off Layer Damping Treatments for Beams
Volume 10: Mechanics of Solids and Structures Parts A and B, 2007Co-Authors: Jessica Yellin, I Y Shen, Per G ReinhallAbstract:Passive stand-off layer (PSOL) and slotted stand-off layer (SSOL) Damping Treatments are presently being implemented in many commercial and defense designs. In a PSOL Damping Treatment, a stand-off or spacer layer is added to a conventional passive constrained layer Damping Treatment. In an SSOL Damping Treatment, slots are included in the stand-off layer. A set of experiments using PSOL and SSOL beams in which the geometric properties of the stand-off layer were varied was conducted to analyze the contribution of the stand-off layer to the overall system Damping. This set of experiments measured the frequency response functions for a series of beams in which the total slotted area of the stand-off layer was held constant while the number of slots in the stand-off layer was increased for a constant stand-off layer material. Finite element analysis models were developed in ANSYS to compare the predicted frequency response functions with the experimentally measured frequency response functions for the beams treated with PSOL and SSOL Damping Treatments. In these beams, the bonding layers used to fabricate these Treatments were found to have a measurable and significant effect on the frequency response of the structure. The finite element model presented here thus included an epoxy layer between the base beam and the stand-off layer, a contact cement layer between the stand-off layer and the viscoelastic layer, and a method for modeling delamination.Copyright © 2007 by ASME
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experimental and finite element analysis of stand off layer Damping Treatments for beams
Smart Structures and Materials 2005: Damping and Isolation, 2005Co-Authors: Jessica Yellin, I Y Shen, Per G ReinhallAbstract:Passive stand-off layer (PSOL) and slotted stand-off layer (SSOL) Damping Treatments are presently being implemented in many commercial and defense designs. In a PSOL Damping Treatment, a stand-off or spacer layer is added to a conventional passive constrained layer Damping Treatment. In an SSOL Damping Treatment, slots are included in the stand-off layer. A set of experiments using PSOL and SSOL beams in which the geometric properties of the stand-off layer were varied was conducted to analyze the contribution of the stand-off layer to the overall system Damping. This set of experiments measured the frequency response functions for a series of beams in which the total slotted area of the stand-off layer was held constant while the number of slots in the stand-off layer was increased for a constant stand-off layer material. Finite element analysis models were developed in ANSYS to compare the predicted frequency response functions with the experimentally measured frequency response functions for the beams treated with PSOL and SSOL Damping Treatments. In these beams, the bonding layers used to fabricate these Treatments were found to have a measurable and significant effect on the frequency response of the structure. The finite element model presented here thus included an epoxy layer between the base beam and the stand-off layer, a contact cement layer between the stand-off layer and the viscoelastic layer, and a method for modelling delamination.
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Analytical model for a one-dimensional slotted stand-off layer Damping Treatment
Smart Structures and Materials 2000: Damping and Isolation, 2000Co-Authors: Jessica Yellin, I Y Shen, Per G ReinhallAbstract:Passive stand-off layer and slotted stand-off layer Damping Treatments are presently being implemented in many commercial and defense designs. In a passive stand-off layer Damping Treatment, a stand-off or spacer layer is added to a conventional passive constrained layer Damping Treatment. Additionally, this stand-off layer can be slotted in order to reduce the bending rigidity and total mass of the Damping Treatment. A preliminary analytical model has being developed for a slotted stand-off layer Damping Treatment applied to a beam. This mathematical model is based on Euler-Bernoulli beam theory, and may be able to provide an analytical solution of the frequency response for a beam treated with slotted stand- off layer Damping.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
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An Analytical and Experimental Analysis for a One-Dimensional Passive Stand-Off Layer Damping Treatment
Journal of Vibration and Acoustics, 2000Co-Authors: Jessica Yellin, I Y Shen, Per G Reinhall, Peter Y. H. HuangAbstract:Passive stand-off layer (PSOL) Damping Treatments are presently being implemented in many commercial and defense designs. In a passive stand-off layer Damping Treatment, a stand-off or spacer layer is added to a conventional passive constrained layer (PCL) Damping Treatment. An analytical model which quantifies the bending and shearing contributions of the stand-off layer has been developed for a passive stand-off layer Damping Treatment applied to a beam. The equations of motion were derived and solved in order to simulate the frequency responses of several beams treated with passive stand-off layer Damping. A series of experiments was conducted in order to test this analytical model. These experiments measured the frequency responses of a variety of beams treated with passive stand-off layer Damping Treatments. The experimentally measured results were normalized and calibrated and then compared with the theoretical predictions using the new analytical model. This comparison showed that the analytical model was able to predict very accurately the frequency responses of the beams treated with passive stand-off layer Damping.
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Experimental investigation of a passive stand-off layer Damping Treatment applied to an Euler-Bernoulli beam
Smart Structures and Materials 1999: Passive Damping and Isolation, 1999Co-Authors: Jessica Yellin, I Y Shen, Per G Reinhall, Peter Y. H. HuangAbstract:Passive stand-off layer (PSOL) Damping Treatments are presently being implemented in many aerospace and defense designs. In a PSOL Damping Treatment, a stand-off or spacer layer is added to a conventional passive constrained layer (PCL) Damping Treatment. The addition of this stand-off layer increases the distance of the viscoelastic and constraining layers from the neutral axis of the vibrating structure. This is thought to enhance the Damping by increasing the shear angle of the viscoelastic layer. In this experimental study, a PSOL Damping Treatment was applied to an Euler-Bernoulli beam. The frequency response of the treated PSOL beam was then compared with a conventionally treated PCL beam of similar dimensions and materials. Previous theoretical studies indicated that PSOL Treatments provided greater Damping than similarly sized conventional PCL Treatments. This study verified experimentally that the beam treated with PSOL had greater Damping of the first four modes than a similarly sized beam treated with PCL.
Wei Zhang - One of the best experts on this subject based on the ideXlab platform.
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global dynamics of composite panels with free layer Damping Treatment in subsonic flow
Composite Structures, 2017Co-Authors: Sha Zhou, Xiaodong Yang, Wei ZhangAbstract:Abstract Global dynamics of forcedly excited composite panels with free layer Damping Treatment in subsonic flow near the first-order critical velocity is investigated. Hamilton’s principle is implemented to derive the PDE of such fluid-structure interaction systems. Then the governing equation is transformed into a discretized nonlinear gyroscopic system via assumed modes and Galerkin’s method. The canonical transformations and normal form theory are applied to reduce the equations of motion to near-integrable Hamiltonian standard forms considering zero to one internal resonance. The Energy-Phase method is employed to demonstrate the existence of chaotic dynamics by identifying the existence of multi-pulse jumping orbits in the perturbed phase space. In both the Hamiltonian and the dissipative perturbation case, the homoclinic trees which describe the repeated bifurcations of multi-pulse solutions are demonstrated. In the case of dissipative perturbation, the existence of generalized Silnikov’s type of orbits which are homoclinic to fixed points on the slow manifold are examined and the parameter region for which the dynamical system may exhibit chaotic motions in the sense of Smale horseshoes are obtained analytically. The present research illustrates that the existence of multi-pulse homoclinic orbits can provide a mechanism for how energy flow from the high-frequency mode to the low-frequency mode. The global results are finally interpreted in terms of the physical traveling wave motion of such gyroscopic continua.
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homoclinic orbits and chaos of a supercritical composite panel with free layer Damping Treatment in subsonic flow
Composite Structures, 2017Co-Authors: Sha Zhou, Xiaodong Yang, Wei ZhangAbstract:Abstract Multi-pulse homoclinic orbits and chaotic dynamics of a supercritical composite panel with free layer Damping Treatment in subsonic flow are investigated considering one to two internal resonance. Inviscid potential flow theory is employed to exhibit the aerodynamic pressure and Kelvin’s model is used to describe the viscoelastic property of the free Damping layer. By Hamilton’s principle, the governing equation of the composite panel in the subcritical regime is derived. In the supercritical regime, the buckling configuration is solved analytically and the PDE is obtained by introducing a displacement transformation for nontrivial equilibrium configuration. Then the governing equation in the first supercritical region is transformed into a discretized nonlinear gyroscopic system via assumed modes and then Galerkin’s method. The method of multiple scales and canonical transformation are applied to reduce the equations of motions to the near-integrable Hamiltonian standard forms. The Energy-Phase method is employed to demonstrate the existence of chaotic dynamics by identifying the existence of multi-pulse jumping orbits in the perturbed phase space. The global solutions are finally interpreted in terms of the physical motion of the gyroscopic continua and the dynamical mechanism of chaotic pattern conversion between the forward traveling wave motion and the complex bidirectional traveling wave motion are discussed.
Jessica Yellin - One of the best experts on this subject based on the ideXlab platform.
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Experimental and Finite Element Analysis of Stand-Off Layer Damping Treatments for Beams
Volume 10: Mechanics of Solids and Structures Parts A and B, 2007Co-Authors: Jessica Yellin, I Y Shen, Per G ReinhallAbstract:Passive stand-off layer (PSOL) and slotted stand-off layer (SSOL) Damping Treatments are presently being implemented in many commercial and defense designs. In a PSOL Damping Treatment, a stand-off or spacer layer is added to a conventional passive constrained layer Damping Treatment. In an SSOL Damping Treatment, slots are included in the stand-off layer. A set of experiments using PSOL and SSOL beams in which the geometric properties of the stand-off layer were varied was conducted to analyze the contribution of the stand-off layer to the overall system Damping. This set of experiments measured the frequency response functions for a series of beams in which the total slotted area of the stand-off layer was held constant while the number of slots in the stand-off layer was increased for a constant stand-off layer material. Finite element analysis models were developed in ANSYS to compare the predicted frequency response functions with the experimentally measured frequency response functions for the beams treated with PSOL and SSOL Damping Treatments. In these beams, the bonding layers used to fabricate these Treatments were found to have a measurable and significant effect on the frequency response of the structure. The finite element model presented here thus included an epoxy layer between the base beam and the stand-off layer, a contact cement layer between the stand-off layer and the viscoelastic layer, and a method for modeling delamination.Copyright © 2007 by ASME
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experimental and finite element analysis of stand off layer Damping Treatments for beams
Smart Structures and Materials 2005: Damping and Isolation, 2005Co-Authors: Jessica Yellin, I Y Shen, Per G ReinhallAbstract:Passive stand-off layer (PSOL) and slotted stand-off layer (SSOL) Damping Treatments are presently being implemented in many commercial and defense designs. In a PSOL Damping Treatment, a stand-off or spacer layer is added to a conventional passive constrained layer Damping Treatment. In an SSOL Damping Treatment, slots are included in the stand-off layer. A set of experiments using PSOL and SSOL beams in which the geometric properties of the stand-off layer were varied was conducted to analyze the contribution of the stand-off layer to the overall system Damping. This set of experiments measured the frequency response functions for a series of beams in which the total slotted area of the stand-off layer was held constant while the number of slots in the stand-off layer was increased for a constant stand-off layer material. Finite element analysis models were developed in ANSYS to compare the predicted frequency response functions with the experimentally measured frequency response functions for the beams treated with PSOL and SSOL Damping Treatments. In these beams, the bonding layers used to fabricate these Treatments were found to have a measurable and significant effect on the frequency response of the structure. The finite element model presented here thus included an epoxy layer between the base beam and the stand-off layer, a contact cement layer between the stand-off layer and the viscoelastic layer, and a method for modelling delamination.
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Analytical model for a one-dimensional slotted stand-off layer Damping Treatment
Smart Structures and Materials 2000: Damping and Isolation, 2000Co-Authors: Jessica Yellin, I Y Shen, Per G ReinhallAbstract:Passive stand-off layer and slotted stand-off layer Damping Treatments are presently being implemented in many commercial and defense designs. In a passive stand-off layer Damping Treatment, a stand-off or spacer layer is added to a conventional passive constrained layer Damping Treatment. Additionally, this stand-off layer can be slotted in order to reduce the bending rigidity and total mass of the Damping Treatment. A preliminary analytical model has being developed for a slotted stand-off layer Damping Treatment applied to a beam. This mathematical model is based on Euler-Bernoulli beam theory, and may be able to provide an analytical solution of the frequency response for a beam treated with slotted stand- off layer Damping.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
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An Analytical and Experimental Analysis for a One-Dimensional Passive Stand-Off Layer Damping Treatment
Journal of Vibration and Acoustics, 2000Co-Authors: Jessica Yellin, I Y Shen, Per G Reinhall, Peter Y. H. HuangAbstract:Passive stand-off layer (PSOL) Damping Treatments are presently being implemented in many commercial and defense designs. In a passive stand-off layer Damping Treatment, a stand-off or spacer layer is added to a conventional passive constrained layer (PCL) Damping Treatment. An analytical model which quantifies the bending and shearing contributions of the stand-off layer has been developed for a passive stand-off layer Damping Treatment applied to a beam. The equations of motion were derived and solved in order to simulate the frequency responses of several beams treated with passive stand-off layer Damping. A series of experiments was conducted in order to test this analytical model. These experiments measured the frequency responses of a variety of beams treated with passive stand-off layer Damping Treatments. The experimentally measured results were normalized and calibrated and then compared with the theoretical predictions using the new analytical model. This comparison showed that the analytical model was able to predict very accurately the frequency responses of the beams treated with passive stand-off layer Damping.
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Experimental investigation of a passive stand-off layer Damping Treatment applied to an Euler-Bernoulli beam
Smart Structures and Materials 1999: Passive Damping and Isolation, 1999Co-Authors: Jessica Yellin, I Y Shen, Per G Reinhall, Peter Y. H. HuangAbstract:Passive stand-off layer (PSOL) Damping Treatments are presently being implemented in many aerospace and defense designs. In a PSOL Damping Treatment, a stand-off or spacer layer is added to a conventional passive constrained layer (PCL) Damping Treatment. The addition of this stand-off layer increases the distance of the viscoelastic and constraining layers from the neutral axis of the vibrating structure. This is thought to enhance the Damping by increasing the shear angle of the viscoelastic layer. In this experimental study, a PSOL Damping Treatment was applied to an Euler-Bernoulli beam. The frequency response of the treated PSOL beam was then compared with a conventionally treated PCL beam of similar dimensions and materials. Previous theoretical studies indicated that PSOL Treatments provided greater Damping than similarly sized conventional PCL Treatments. This study verified experimentally that the beam treated with PSOL had greater Damping of the first four modes than a similarly sized beam treated with PCL.
N. Ganesan - One of the best experts on this subject based on the ideXlab platform.
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DYNAMIC STUDIES ON BEAMS WITH UNCONSTRAINED LAYER Damping Treatment
Journal of Sound and Vibration, 1996Co-Authors: P.k. Roy, N. GanesanAbstract:The dynamics of a beam treated with an unconstrained Damping layer are investigated. The Damping layer is applied either uniformly or in a distributed fashion. The effect of the distributed Damping layer Treatment on the dynamic displacement and the stresses are studied. The beam is subjected to a point harmonic excitation at the first three natural frequencies. It is found that the use of a distributed layer Damping Treatment can reduce the requirement of added material considerably. Or, in other words, a considerable amount of reduction in the dynamic stresses and the dynamic displacements can be obtained for the same amount of added Damping layer material.
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The harmonic response of cylindrical shells with constrained Damping Treatment
Journal of Sound and Vibration, 1995Co-Authors: T.c. Ramesh, N. GanesanAbstract:Abstract The harmonic response of cylindrical shells with constrained Damping Treatment is studied by the finite element method. Two finite elements based on different kinematic hypothesis are presented and made use of in the study. Studies are carried out and results presented for shells with different core to facing thickness ratios, length to radius and boundary conditions.
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Vibration and Damping analysis of conical shells with constrained Damping Treatment
Finite Elements in Analysis and Design, 1993Co-Authors: T.c. Ramesh, N. GanesanAbstract:Abstract This paper presents an analysis of conical shells with a constrained viscoelastic Damping Treatment. A finite element based on a discrete layer theory is developed for the purpose. The effects of core-to-facing thickness ratio, slant length and semi vertex angle of the cone on the frequencies and loss factors of conical shells with isotropic facings are investigated for three boundary conditions: clamped at both ends, simply supported at both ends and clamped at the small end. The effect of the shear parameter on the frequency and loss factor is also presented.
