Characteristics of Enhanced Active Constrained Layer Damping Treatments With Edge Elements: Part I — Finite Element Model Development and Validation

1997 ◽  
Author(s):  
W. H. Liao ◽  
K. W. Wang
Keyword(s):  
Finite Element ◽  
Model Development ◽  
Element Model ◽  
System Model ◽  
Constrained Layer Damping ◽  
Active System ◽  
Edge Elements ◽  
Active Constrained Layer Damping ◽  
Viscoelastic Modeling ◽  
Active Constrained Layer

Abstract This paper is concerned with the enhanced active constrained layer (EACL) damping treatment with edge elements. A finite element time-domain-based model (FEM) is developed for the beam structure with partially covered EACL. The edge elements are modeled as equivalent springs mounted at the boundaries of the piezoelectric layer. The transverse, axial, and shear motions are included. The energy method in combination with the Golla-Hughes-McTavish (GHM) viscoelastic modeling method is used. The GHM dissipation coordinates can describe the frequency-dependent viscoelastic material properties. This model becomes the current active constrained layer (ACL) system model as the stiffness of the edge elements approaches zero. Without the edge elements and viscoelastic materials, the purely active system model can also be obtained from the EACL model as a special case. Lab tests are conducted to validate the models. The frequency responses of the EACL, current ACL, and purely active systems predicted by the FEM match the test results closely. Utilizing these models, analysis results are illustrated and discussed in Part (II) of this paper.

Characteristics of Enhanced Active Constrained Layer Damping Treatments With Edge Elements, Part 1: Finite Element Model Development and Validation

1998 ◽  
Vol 120 (4) ◽  
pp. 886-893 ◽  
Author(s):  
W. H. Liao ◽  
K. W. Wang
Keyword(s):  
Finite Element ◽  
Model Development ◽  
Element Model ◽  
System Model ◽  
Viscoelastic Layer ◽  
Constrained Layer Damping ◽  
Active System ◽  
Edge Elements ◽  
Active Constrained Layer Damping ◽  
Active Constrained Layer

This paper is concerned with the enhanced active constrained layer (EACL) damping treatment with edge elements. A finite element time-domain-based model (FEM) is developed for the beam structure with partially covered EACL. The edge elements are modeled as equivalent springs mounted at the boundaries of the piezoelectric layer. The Golla-Hughes-McTavish (GHM) method is used to model the viscoelastic layer. The GHM dissipation coordinates can describe the frequency-dependent viscoelastic material properties. This model becomes the current active constrained layer (ACL) system model as the stiffness of the edge elements approaches zero. Without the edge elements and viscoelastic materials, the purely active system model can also be obtained from the EACL model as a special case. Lab tests are conducted to validate the models. The frequency responses of the EACL, current ACL, and purely active systems predicted by the FEM match the test results closely. Utilizing these models, analysis results are illustrated and discussed in Part (2) of this paper.

Active Control of Vibration and Noise Radiation from Fluid-Loaded Cylinder using Active Constrained Layer Damping

2002 ◽  
Vol 8 (6) ◽  
pp. 877-902 ◽  
Author(s):  
W. Laplante ◽  
T. Chen ◽  
A. Baz ◽  
W. Sheilds
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Acoustic Radiation ◽  
Sound Radiation ◽  
Element Model ◽  
Water Tank ◽  
Constrained Layer Damping ◽  
Active Constrained Layer Damping ◽  
Active Constrained Layer ◽  
Surrounding Fluid

Vibration and sound radiation from fluid-loaded cylindrical shells are controlled using patches of Active Constrained Layer Damping (ACLD). The performance and the enhanced damping characteristics via reduced vibrations and sound radiation in the surrounding fluid is demonstrated both theoretically and experimentally. A prime motivation for this work is the potential wide applications in submarines and torpedoes where acoustic stealth is critical to the effectiveness of missions. A finite element model is also developed to predict the vibration and the acoustic radiation in the surrounding fluid of the ACLD-treated cylinders. The developed model is used to study the effectiveness of the control and placement strategies of the ACLD in controlling the fluid-structure interactions. A water tank is constructed that incorporates test cylinders treated with two ACLD patches placed for targeting specific vibration modes. Using this arrangement, the effectiveness of different control strategies is studied when the submerged cylinders are subjected to internal excitation, and the radiated sound pressure level in the water is observed. Comparisons are made between the experimental results and the theoretical predictions to validate the finite element model.

scholarly journals Active Constrained Layer Damping of Smart Skew Laminated Composite Plates Using 1–3 Piezoelectric Composites

2013 ◽  
Vol 2013 ◽  
pp. 1-17 ◽  
Author(s):  
R. M. Kanasogi ◽  
M. C. Ray
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Laminated Composite ◽  
Composite Plates ◽  
Element Model ◽  
Constrained Layer Damping ◽  
Laminated Composite Plates ◽  
Piezoelectric Composites ◽  
Active Constrained Layer Damping ◽  
Active Constrained Layer

This paper deals with the analysis of active constrained layer damping (ACLD) of smart skew laminated composite plates. The constraining layer of the ACLD treatment is composed of the vertically/obliquely reinforced 1–3 piezoelectric composites (PZCs). A finite element model has been developed for accomplishing the task of the active constrained layer damping of skew laminated symmetric and antisymmetric cross-ply and antisymmetric angle-ply composite plates integrated with the patches of such ACLD treatment. Both in-plane and out-of-plane actuations by 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. Particular emphasis has been placed on investigating the performance of the patches when the orientation angle of the piezoelectric fibers of the constraining layer is varied in the two mutually orthogonal vertical planes. Also, the effects of varying the skew angle of the substrate laminated composite plates and different boundary conditions on the performance of the patches have been studied. The analysis reveals that the vertically and the obliquely reinforced 1–3 PZC materials should be used for achieving the best control authority of ACLD treatment, as the boundary conditions of the smart skew laminated composite plates are simply supported and clamped-clamped, respectively.

Characteristics of Enhanced Active Constrained Layer Damping Treatments With Edge Elements: Part II — System Analysis

1997 ◽  
Author(s):  
W. H. Liao ◽  
K. W. Wang
Keyword(s):  
System Analysis ◽  
Careful Analysis ◽  
Constrained Layer Damping ◽  
Passive Damping ◽  
Active System ◽  
Control Effort ◽  
Edge Elements ◽  
Active Constrained Layer Damping ◽  
Critical Edge ◽  
Active Constrained Layer

Abstract This paper presents some important characteristics of enhanced active constrained layer damping (EACL) treatments for vibration controls. Specific interests are on understanding how the edge elements will influence the active action authority, the passive damping ability, and their combined effects in EACL. Analysis results indicate that the edge elements can significantly improve the active action transmissibility of the current active constrained layer damping (ACL) treatment due to the bypass effect. Although the edge elements will slightly reduce the viscoelastic material (VEM) passive damping, the EACL will still have significant damping from the VEM. Combining the overall active and passive actions, the new EACL with sufficiently stiff edge elements not only could achieve better performance with less control effort compared to the current ACL system, but also could outperform the purely active system. With careful analysis, we can map out the required critical edge element stiffness for successful designs. In addition, analysis also shows that the EACL treatment is a more robust design. That is, it could outperform both the purely active and passive systems throughout a much broader design space than the current ACL configuration. With these desirable characteristics, the EACL could be used to realize an overall optimal active-passive hybrid system.

Characteristics of Enhanced Active Constrained Layer Damping Treatments With Edge Elements, Part 2: System Analysis

1998 ◽  
Vol 120 (4) ◽  
pp. 894-900 ◽  
Author(s):  
W. H. Liao ◽  
K. W. Wang
Keyword(s):  
System Analysis ◽  
Careful Analysis ◽  
Constrained Layer Damping ◽  
Passive Damping ◽  
Active System ◽  
Control Effort ◽  
Edge Elements ◽  
Active Constrained Layer Damping ◽  
Critical Edge ◽  
Active Constrained Layer

This paper presents some important characteristics of enhanced active constrained layer damping (EACL) treatments for vibration controls. Specific interests are on understanding how the edge elements will influence the active action authority, the passive damping ability, and their combined effects in EACL. Analysis results indicate that the edge elements can significantly improve the active action transmissibility of the current active constrained layer damping (ACL) treatment. Although the edge elements will slightly reduce the viscoelastic material (VEM) passive damping, the EACL will still have significant damping from the VEM. Combining the overall active and passive actions, the new EACL with sufficiently stiff edge elements not only could achieve better performance with less control effort compared to the current ACL system, but also could outperform the purely active system. With careful analysis, we can map out the required critical edge element stiffness for successful designs. In addition, analysis also shows that the EACL treatment is a more robust design. That is, it could outperform both the purely active and passive systems throughout a much broader design space than the current ACL configuration. With these desirable characteristics, the EACL could be used to realize an overall optimal active-passive hybrid system.

scholarly journals Vibration Control of an Aero Pipeline System with Active Constraint Layer Damping Treatment

2019 ◽  
Vol 9 (10) ◽  
pp. 2094 ◽  
Author(s):  
Jingyu Zhai ◽  
Jiwu Li ◽  
Daitong Wei ◽  
Peixin Gao ◽  
Yangyang Yan ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Vibration Control ◽  
Element Model ◽  
Control Voltage ◽  
Pipeline System ◽  
Constrained Layer Damping ◽  
Active Constraint ◽  
Active Constrained Layer Damping ◽  
Active Constrained Layer

In this paper, vibration control of an aero pipeline system using active constrained layer damping treatment has been investigated in terms of the vibration and stress distribution. A three-dimensional finite element model of such a pipeline with active constrained layer damping (ACLD) patches is developed. The transfer of the driving force under harmonic voltage is analyzed based on the finite element model. The vibration control of the pipeline with active constrained layer damping treatment under different voltages is computed to analyze the influence of control parameters and structural parameters on the control effect. An experiment platform is developed to validate the above relations. Results show that the performance of the active constrained layer damping treatment is affected by the elastic modulus and thickness of the viscoelastic layer, control voltage and structure size. The performance increases significantly with the rising of the control voltage and cover area of ACLD patches among these parameters.

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