Active Constrained Layer Damping Patches Research Articles

Analysis and active control for wind induced vibration of beam with ACLD patch

The structural vibration suppression with active constrained layer damping (ACLD) was widely studied recently. However, the literature seldom concerned with the vibration control on flow-induced vibration using active constrained layer. In this paper the wind induced vibration of cantilevered beam is analyzed and suppressed by using random theory together with a velocity feedback control strategy. The piezoelectric material and frequency dependent viscoelastic layer are used to achieve effective active damping in the vibration control. The transverse displacement and velocity in time and frequency domains, as well as the power spectral density and the mean-square value of the transverse displacement and velocity, are formulated under wind pressure at variable control gain. It is observed from the numerical results that the wind induced vibration can be significantly suppressed by using a small outside active voltage on the constrained layer.

Control of geometrically nonlinear vibrations of skew laminated composite plates using skew or rectangular 1–3 piezoelectric patches

This paper deals with the analysis of active constrained layer damping (ACLD) of geometrically nonlinear transient vibrations of skew laminated composite plates using skew or rectangular patches of the ACLD treatment. The constraining layer of the patch of the ACLD treatment is composed of the vertically/obliquely reinforced 1–3 piezoelectric composite material. The Golla–Hughes–McTavish method has been used to model the constrained viscoelastic layer of the ACLD treatment in the time domain. A coupled electromechanical nonlinear three dimensional finite element model of skew laminated thin composite plates integrated with the skew or rectangular patches of ACLD treatment has been derived. The performance of the patches is investigated for different configurations of their placements on the top surface of the skew substrate plates. The analysis reveals that the ACLD treatment significantly improves the active damping characteristics of the skew laminated composite plates over the passive damping for suppressing their geometrically nonlinear transient vibrations. It is found that even though the substrate laminated plates are skew, a rectangular patch of the ACLD treatment located at the centre of the top surface of the substrate should be used for optimum damping of geometrically nonlinear vibrations of skew laminated composite plates irrespective of their skew angles and boundary conditions. The effects of piezoelectric fiber orientation angle and the skew angles of the substrate plates on the control authority of the ACLD patches have been emphatically investigated.

Smart control of nonlinear vibrations of doubly curved functionally graded laminated composite shells under a thermal environment using 1–3 piezoelectric composites

This paper addresses the active control of geometrically nonlinear vibrations of doubly curved functionally graded (FG) laminated composite shells integrated with a patch of active constrained layer damping (ACLD) treatment under the thermal environment. Vertically/obliquely reinforced 1-3 piezoelectric composite (PZC) and active fiber composite (AFC) are used as the materials of the constraining layer of the ACLD treatment. Each layer of the substrate FG laminated composite shell is made of fiber-reinforced composite material in which the fibers are longitudinally aligned in the plane parallel to the top or bottom surface of the layer and the layer is assumed to be graded in the thickness direction by way of varying the fiber orientation angle across its thickness according to a power law. The novelty of the present work is that, unlike the traditional laminated composite shells, the FG laminated composite shells are constructed in such a way that the continuous variation of material properties and stresses across the thickness of the shell is achieved. The Golla-Hughes-McTavish (GHM) method has been implemented to model the constrained viscoelastic layer of the ACLD treatment in time domain. Based on the first-order shear deformation theory (FSDT), a finite element (FE) model has been developed to model the open-loop and closed-loop nonlinear dynamics of the overall FG laminated composite shell under a thermal environment. Both symmetric and asymmetric FG laminated composite doubly curved shells are considered for presenting the numerical results. The analysis suggests that the ACLD patch significantly improves the damping characteristics of the doubly curved FG laminated composite shells for suppressing their geometrically nonlinear transient vibrations. It is found that the performance of the ACLD patch with its constraining layer being made of the AFC material is significantly higher than that of the ACLD patch with vertically/obliquely reinforced 1-3 PZC constraining layer. The effects of variation of piezoelectric fiber orientation in both the obliquely reinforced 1-3 PZC and the AFC constraining layers on the control authority of the ACLD patch have also been investigated.

Active control of geometrically nonlinear vibrations of doubly curved smart sandwich shells using 1–3 piezoelectric composites

This paper deals with the analysis of active damping of geometrically nonlinear vibrations of doubly curved smart sandwich shells integrated with a patch of active constrained layer damping (ACLD) treatment. The substrate sandwich shell is composed of orthotropic laminated composite faces separated by a thick flexible core. The constraining layer of the ACLD treatment is made of the vertically/obliquely reinforced 1–3 piezoelectric composites (PZCs). The constrained viscoelastic layer is modeled using the Golla–Hughes–McTavish (GHM) method in the time domain. A three dimensional finite element (FE) model has been developed to study this coupled nonlinear electro-elastic problem. The numerical results indicate that the ACLD patch significantly improves the damping characteristics of the paraboloid and hyperboloid sandwich shells with laminated cross-ply and angle-ply facings for suppressing their geometrically nonlinear vibrations. Particular emphasis has been placed on investigating the effect of the variation of piezoelectric fiber orientation angle on the performance of the ACLD treatment. Unlike the doubly curved laminated composite shells, the performance of the ACLD treatment becomes maximum for causing active damping of geometrically nonlinear vibrations of doubly curved sandwich shells with laminated composite facings if the constraining layer of the treatment is made of obliquely reinforced 1–3 PZC.

SMART CONTROL OF NONLINEAR VIBRATIONS OF LAMINATED PLATES USING ACTIVE FIBER COMPOSITES

This paper deals with the geometrically nonlinear dynamic analysis of smart laminated composite plates integrated with the patches of active constrained layer damping (ACLD) treatment. The constraining layer of the ACLD treatment is made of active fiber composite (AFC) materials. The Von Kármán type nonlinear strain–displacement relations and the first-order shear deformation theory (FSDT) are adopted in deriving the coupled electromechanical nonlinear finite element (FE) model. The Golla–Hughes–McTavish (GHM) method is implemented to model the constrained viscoelastic layer of the ACLD treatment in time domain. Symmetric/antisymmetric cross-ply and antisymmetric angle-ply laminated substrate plates are considered in the numerical analyses. The results indicate that the ACLD patches significantly improve the damping characteristics of the plates for suppressing the geometrically nonlinear transient vibrations of the plates. The effects of variation of piezoelectric fiber orientation in the AFC constraining layer on the control authority of the ACLD patches have also been investigated.

Active control of geometrically nonlinear transient vibrations of laminated composite cylindrical panels using piezoelectric fiber reinforced composite

This paper addresses the analysis of active constrained layer damping (ACLD) of geometrically nonlinear transient vibrations of laminated thin composite cylindrical panels using piezoelectric-fiber- reinforced composite (PFRC) materials. The constraining layer of the ACLD treatment is considered to be made of the PFRC materials. The Golla–Hughes–McTavish (GHM) method has been implemented to model the constrained viscoelastic layer of the ACLD treatment in time domain. The Von Karman type-nonlinear strain-displacement relations and a simple first-order shear deformation theory are used for deriving this electromechanical coupled problem. A three-dimensional finite element (FE) model of smart composite panels integrated with the patches of such ACLD treatment has been developed to demonstrate the performance of these patches on enhancing the damping characteristics of thin symmetric and antisymmetric laminated cylindrical panels in controlling the geometrically nonlinear transient vibrations. The numerical results indicate that the ACLD patches significantly improve the damping characteristics of both symmetric and antisymmetric panels for suppressing the geometrically nonlinear transient vibrations of the panels. The effect of the shallowness angle of the panels on the control authority of the patches has also been investigated.

Active constrained layer damping of geometrically nonlinear vibrations of smart laminated composite sandwich plates using 1–3 piezoelectric composites

This paper deals with the analysis of active constrained layer damping (ACLD) of geometrically nonlinear vibrations of sandwich plate with orthotropic laminated composite faces separated by a flexible core. The constraining layer of the ACLD treatment is composed of the vertically/obliquely reinforced 1–3 piezoelectric composites. The Golla–Hughes–McTavish method has been implemented to model the constrained viscoelastic layer of the ACLD treatment in time domain. The first-order shear deformation theory and the Von Karman type nonlinear strain displacement relations are used for analyzing this coupled electro-elastic problem. A three dimensional finite element model of smart laminated composite sandwich plate integrated with ACLD patches has been developed to investigate the performance of these patches for controlling the geometrically nonlinear vibrations of the plates. The numerical results indicate that the ACLD patches significantly improve the damping characteristics of the sandwich plates with laminated cross-ply and angle-ply facings for suppressing their geometrically nonlinear vibrations. Particular emphasis has been placed on investigating the effect of the variation of piezoelectric fiber orientation angle on the performance of the ACLD treatment.

Active damping of geometrically nonlinear vibrations of laminated composite plates using vertically reinforced 1-3 piezoelectric composites

This paper addresses the analysis of active constrained layer damping (ACLD) of geometrically nonlinear transient vibrations of laminated composite plates using vertically reinforced 1-3 piezoelectric composite (PZC) as the material of the constraining layer of the ACLD treatment. The Von Karman type nonlinear strain-displacement relations and the first-order shear deformation theory (FSDT) are used for deriving the coupled electromechanical nonlinear finite element model. The Golla–Hughes–McTavish (GHM) method has been used to model the constrained viscoelastic layer of the ACLD treatment in the time domain. The numerical results indicate that the ACLD patches significantly improve the damping characteristics of the cross-ply and antisymmetric angle-ply plates for suppressing the geometrically nonlinear transient vibrations of the plates.

Active control of laminated composite truncated conical shells using vertically and obliquely reinforced 1-3 piezoelectric composites

This paper deals with the analysis of active control of vibration of thin laminated composite truncated circular conical shells using vertically and obliquely reinforced 1-3 piezoelectric composite (PZC) materials as the constraining layer of the active constrained layer damping (ACLD) treatment. A finite element model of smart truncated conical laminated shells integrated with the patches of such ACLD treatment has been developed to demonstrate the performance of these patches on enhancing the damping characteristics of thin symmetric and antisymmetric cross-ply and antisymmetric angle-ply laminated truncated conical shells. Velocity feedback control loop has been implemented to activate the patches. The effect of variation of semi-cone angle on the performance of the patches for controlling first few modes of the truncated conical laminated shells has been demonstrated. Emphasis has also been placed on exploring the effect of variation of piezoelectric fiber orientation angle in the constraining layer on the control authority of the ACLD patches.

Active damping of geometrically nonlinear vibrations of doubly curved laminated composite shells

This paper deals with the analysis of active constrained layer damping ( ACLD) of geometrically nonlinear transient vibrations of doubly curved laminated composite shells. Vertically/obliquely reinforced 1–3 piezoelectric composite ( PZC) and active fiber composite ( AFC) materials are used as the materials of the constraining layer of the ACLD treatment. The Golla–Hughes–McTavish (GHM) method has been implemented to model the constrained viscoelastic layer of the ACLD treatment in time domain. The first-order shear deformation theory ( FSDT) and the Von Kármán type non-linear strain displacement relations are used for analyzing this coupled electro-elastic problem. A three dimensional finite element ( FE) model of doubly curved laminated smart composite shells integrated with ACLD patches has been developed to investigate the performance of these patches for controlling the geometrically nonlinear transient vibrations of the shells. The numerical results indicate that the ACLD patches significantly improve the damping characteristics of the doubly curved laminated cross-ply and angle-ply shells for suppressing their geometrically nonlinear transient vibrations. It is found that the performance of the ACLD patch with its constraining layer being made of the AFC is significantly higher than that of the ACLD patch with vertically/obliquely reinforced 1–3 PZC constraining layer. The effects of variation of piezoelectric fiber orientation in both the obliquely reinforced 1–3 PZC and the AFC constraining layers on the control authority of the ACLD patches have also been investigated.

Active Fiber Composites for Smart Damping of Doubly Curved Laminated Shells

This paper deals with the analysis of active constrained layer damping (ACLD) of doubly curved laminated composite shells using active fiber composite (AFC) materials. The constraining layer of the ACLD treatment has been considered to be made of the AFC materials. A three dimensional energy based finite element model of the smart doubly curved laminated composite shell integrated with a patch of such ACLD treatment has been developed to demonstrate the performance of the patch on enhancing the damping characteristics of the doubly curved laminated composite shells. Particular emphasis has been placed on studying the effect of variDWLRQRISLH)RHOHFWULF�oEHURULHQWDWLRQDQJOHLQWKHFRQVWUDLQL QJ� AFC layer on the control authority of the ACLD patch.

Active damping of geometrically nonlinear vibrations of laminated composite shallow shells using vertically/obliquely reinforced 1-3 piezoelectric composites

This paper addresses the analysis of active constrained layer damping (ACLD) of geometrically nonlinear transient vibrations of laminated thin composite cylindrical shallow shells using vertically reinforced 1-3 piezoelectric composite (PZC). The constraining layer of the ACLD treatment is considered to be made of this 1-3 PZC material. The Golla–Hughes–McTavish (GHM) method has been implemented to model the constrained viscoelastic layer of the ACLD treatment in time domain. The Von Karman type non-linear strain displacement relations and the first-order shear deformation theory (FSDT) are used for deriving this electromechanical coupled problem. A three dimensional finite element (FE) model of smart composite shallow shells integrated with a patch of such ACLD treatment has been developed to demonstrate the performance of the patch on enhancing the damping characteristics of thin laminated cylindrical shells, in controlling the geometrically nonlinear transient vibrations. The numerical results indicate that the ACLD patch significantly improves the damping characteristics of the shells for suppressing the geometrically nonlinear transient vibrations of the shells. The effect of variation of fiber orientation in the PZC material on the control authority of the ACLD patch has also been investigated.

Vibration and damping characteristics of cylindrical shells with active constrained layerdamping treatments

In this paper, the application of active constrained layer damping (ACLD) treatments isextended to the vibration control of cylindrical shells. The governing equation of motion ofcylindrical shells partially treated with ACLD treatments is derived on the basis of theconstitutive equations of elastic, piezoelectric and visco-elastic materials and an energyapproach. The damping of a visco-elastic layer is modeled by the complex modulusformula. A finite element model is developed to describe and predict the vibrationcharacteristics of cylindrical shells partially treated with ACLD treatments. A closed-loopcontrol system based on proportional and derivative feedback of the sensor voltagegenerated by the piezo-sensor of the ACLD patches is established. The dynamic behaviorsof cylindrical shells with ACLD treatments such as natural frequencies, loss factors andresponses in the frequency domain are further investigated. The effects of several keyparameters such as control gains, location and coverage of ACLD treatmentson vibration suppression of cylindrical shells are also discussed. The numericalresults indicate the validity of the finite element model and the control strategyapproach. The potential of ACLD treatments in controlling vibration and soundradiation of cylindrical shells used as major critical structures such as cabins ofaircraft, hulls of submarines and bodies of rockets and missiles is thus demonstrated.

Vibration control of beams with active constrained layer damping

An analytical methodology is presented to study the active vibration control of beamstreated with active constrained layer damping (ACLD). This analytical method is based onthe conventional theory of structural dynamics. The process of deriving equations is preciseand easy to understand. Hamilton’s principle with the Rayleigh–Ritz method is usedto derive the equation of motion of the beam/ACLD system. By applying anappropriate external control voltage to activate the piezoelectric constraining layer,a negative velocity feedback control strategy is employed to obtain the activedamping and effective vibration control. From the numerical results it is seenthat the damping performances of the beam can be significantly improved bythe ACLD treatment. With the increase of the control gain, the active dampingcharacteristics are also increased. By equally dividing one ACLD patch into two andproperly distributing them on the beam, one can obtain better active vibrationcontrol results than for the beam with one ACLD patch. The analytical methodpresented in this paper can be effectively extended to other kinds of structures.

Active structural-acoustic control of laminated composite plates using vertically/obliquely reinforced 1–3 piezoelectric composite patch

This article deals with the active structural-acoustic control of thin laminated composite plates using vertically reinforced 1–3 piezoelectric fiber-reinforced composite (PFRC) material for constraining layer of active constrained layer damping (ACLD) treatment. A finite element model is developed for the laminated composite plates integrated with ACLD patches and coupled with acoustic cavity to describe the coupled structural-acoustic behavior of the plates enclosing the cavity. Both in-plane and out of plane actuation of the constraining layer of the ACLD treatment have been utilized for deriving the finite element model. The analysis revealed that the vertical actuation dominates over the in-plane actuation. The performance of PFRC layers of the patches has been investigated for active control of sound radiated from thin symmetric and antisymmetric cross-ply and antisymmetric angle-ply laminated composite plates into the acoustic cavity.

Active constrained layer damping of geometrically nonlinear transient vibrations of composite plates using piezoelectric fiber-reinforced composite

This paper addresses the analysis of active constrained layer damping (ACLD) of geometrically nonlinear transient vibrations of laminated thin composite plates using piezoelectric fiber-reinforced composite (PFRC) materials. The constraining layer of the ACLD treatment is considered to be made of the PFRC materials. The Golla–Hughes–McTavish (GHM) method has been used to model the constrained viscoelastic layer of the ACLD treatment in the time domain. A finite element model has been developed for the cross-ply and antisymmetric angle-ply plates integrated with the patches of ACLD treatment undergoing geometrically nonlinear vibrations. The Von Ka`rma`n-type nonlinear strain displacement relations and the first-order shear deformation theory (FSDT) are used for deriving this coupled electromechanical nonlinear finite element model. The numerical results indicate that the ACLD patches significantly improve the damping characteristics of the cross-ply and antisymmetric angle-ply plates for suppressing the geometrically nonlinear transient vibrations of the plates. Emphasis has also been placed on investigating the effect of variation of fiber orientation in the PFRC material on the control authority of the ACLD patches.

Active constrained layer damping of geometrically nonlinear vibrations of functionallygraded plates using piezoelectric fiber-reinforced composites

In this paper, a geometrically nonlinear dynamic analysis has been presented forfunctionally graded (FG) plates integrated with a patch of active constrained layerdamping (ACLD) treatment and subjected to a temperature field. The constraining layer ofthe ACLD treatment is considered to be made of the piezoelectric fiber-reinforcedcomposite (PFRC) material. The temperature field is assumed to be spatiallyuniform over the substrate plate surfaces and varied through the thickness ofthe host FG plates. The temperature-dependent material properties of the FGsubstrate plates are assumed to be graded in the thickness direction of the platesaccording to a power-law distribution while the Poisson’s ratio is assumed tobe a constant over the domain of the plate. The constrained viscoelastic layerof the ACLD treatment is modeled using the Golla–Hughes–McTavish (GHM)method. Based on the first-order shear deformation theory, a three-dimensional finiteelement model has been developed to model the open-loop and closed-loop nonlineardynamics of the overall FG substrate plates under the thermal environment. Theanalysis suggests the potential use of the ACLD treatment with its constraininglayer made of the PFRC material for active control of geometrically nonlinearvibrations of FG plates in the absence or the presence of the temperature gradientacross the thickness of the plates. It is found that the ACLD treatment is moreeffective in controlling the geometrically nonlinear vibrations of FG plates than incontrolling their linear vibrations. The analysis also reveals that the ACLD patch ismore effective for controlling the nonlinear vibrations of FG plates when it isattached to the softest surface of the FG plates than when it is bonded to the stiffestsurface of the plates. The effect of piezoelectric fiber orientation in the activeconstraining PFRC layer on the damping characteristics of the overall FG plates is alsodiscussed.

Combined feedback/feedforward active control of vibration of beams with ACLD treatments: Numerical simulation

This paper concerns the numerical simulation of feedback, adaptive feedforward and hybrid (combined feedback/feedforward) control systems on the active control of vibrations of beams with Active Constrained Layer Damping (ACLD) treatments. For the simulation a 1-D beam finite element (FE) model with an arbitrary number of elastic, piezoelectric and viscoelastic layers attached to both sides of the beam is utilized. The damping behavior of the viscoelastic layers is considered by a Laplace transformed Anelastic Displacement Fields (ADF) method. The analyzed case study regards the disturbance rejection of an aluminium beam with a pair of surface mounted ACLD patches. In the design and simulation of the control system a Single-Input Single-Output (SISO) configuration with the output being the velocity at one point of the beam and the input being the control voltage applied into the piezoelectric constraining layers is considered. The case study allows to assess and discuss the outcomes and drawbacks of the feedback and feedforward controllers when used individually and the advantages of the hybrid controller.

Multi-objective optimization of an active constrained layer damping treatment for vibrationcontrol of a rotating flexible arm

This paper describes the use of the multi-objective genetic algorithm (MOGA) to solve anintegrated optimization problem of a rotating flexible arm with active constrainedlayer damping (ACLD) treatment. The arm is rotating in a horizontal plane withtriangular velocity profiles. The ACLD patch is placed at the clamped end of the arm.The design objectives are to minimize the total treatment weight, the controlvoltage and the tip displacement of the arm, as well as to maximize the passivedamping characteristic of the arm. Design variables include the control gains,the maximum angular velocity, the shear modulus of the viscoelastic layer, thethickness of the piezoelectric constraining and viscoelastic layers, and the lengthof the ACLD patch. In order to evaluate the effect of different combinations ofdesign variables on the system, the finite element method, in conjunction with theGolla–Hughes–McTavish (GHM) method, is employed to model the flexible arm withACLD treatment to predict its dynamic behavior, in which the effects of centrifugalstiffening due to the rotation of flexible arm are taken into account. As a result ofoptimization, reasonable Pareto solutions are successfully obtained. It is shownthat the MOGA is applicable to the present integrated optimization problem.

Multi-objective optimization of an active constrained layer damping treatment for shapecontrol of flexible beams

This work presents the use of a multi-objective genetic algorithm (MOGA) to solve anintegrated optimization problem for the shape control of flexible beams with an activeconstrained layer damping (ACLD) treatment. The design objectives are to minimize thetotal weight of the system, the input voltages and the steady-state error between theachieved and desired shapes. Design variables include the thickness of the constraining andviscoelastic layers, the arrangement of the ACLD patches, as well as the control gains. Inorder to set up an evaluator for the MOGA, the finite element method (FEM), inconjunction with the Golla–Hughes–McTavish (GHM) method, is employed to model aclamped-free beam with ACLD patches to predict the dynamic behaviour of the system. Asa result of the optimization, reasonable Pareto solutions are successfully obtained. It isshown that ACLD treatment is suitable for shape control of flexible structures andthat the MOGA is applicable to the present integrated optimization problem.