Experimental Studies on Active Vibration Control of a Beam Using Hybrid Active∕Passive Constrained Layer Damping Treatments

2005 ◽  
Vol 127 (5) ◽  
pp. 515-518 ◽  
Author(s):  
Pankaj K. Langote ◽  
P. Seshu
Keyword(s):  
Piezoelectric Materials ◽  
Active Vibration Control ◽  
Experimental Studies ◽  
Time Domain Analysis ◽  
Constrained Layer Damping ◽  
Active Vibration ◽  
The Time Domain ◽  
Damping Treatments ◽  
Passive Constrained Layer Damping ◽  
Hybrid Damping

Hybrid damping designs with active piezoelectric materials and passive viscoelastic materials (VEMs) combine the advantages of both active and passive constrained layer damping treatments. In this study, experiments have been conducted on nine systems viz., bare beam, active damping (AD), passive constrained layer damping (PCLD—three variants) and hybrid active∕passive constrained layer damping (Hybrid AD∕PCLD—four variants). Based on the time domain analysis of these systems, it is shown that the “best” performance is obtained using a hybrid damping configuration wherein the VEM and the piezoelectric layers are acting separately.

Active Vibration Control of Beams By Combining Precompressed Layer Damping and ACLD Treatment: Theory and Experimental Implementation

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
Sanjiv Kumar ◽  
Rakesh Sehgal ◽  
Rajiv Kumar
Keyword(s):  
Equations Of Motion ◽  
Active Vibration Control ◽  
Flexible Structures ◽  
Constrained Layer Damping ◽  
Linear Quadratic ◽  
Active Constrained Layer Damping ◽  
Active Vibration ◽  
Passive Technique ◽  
Failure Conditions ◽  
Passive Constrained Layer Damping

By attaching initially stressed poly vinyl chloride (PVC) layers on the flexible structures, necessary passive damping can be provided. Using passive constrained layers on these PVC layers, the efficiency can be made even better than ordinary passive constrained layer damping (PCLD) treatment. By using stressed PVC layers, a rich performance in case of circuit failure conditions is always available. An active constraining layer further enhances the damping performance of this passive technique. Precompressed layer damping treatment augmented with active constrained layer damping (ACLD) treatment has been suggested, which has many desirable features as compared to existing pretensed layer damping treatment. Such enhancement in damping performance is not possible by conventional ACLD as well as PCLD techniques. The effect of initial strain (compressive or tensile) and other parameters of the PVC layers on the vibration characteristics of flexible structure have been investigated. The Hamilton principle in conjunction with finite element method is used to derive the differential equations of motion. Using proportional feedback controllers, the complex closed loop eigenvalue problem is developed and solved numerically. The effectiveness of the proposed technique has been validated experimentally using a digital linear quadratic Gaussian controller.

scholarly journals Active Piezoelectric Vibration Control of Subscale Composite Fan Blades

2012 ◽  
Author(s):  
Kirsten P. Duffy ◽  
Benjamin B. Choi ◽  
Andrew J. Provenza ◽  
James B. Min ◽  
Nicholas Kray
Keyword(s):  
Vibration Control ◽  
Electromechanical Coupling ◽  
New Technologies ◽  
Piezoelectric Materials ◽  
Fiber Composite ◽  
Damping Ratio ◽  
Active Vibration Control ◽  
Rotor Speed ◽  
Blade Vibration ◽  
Active Vibration

As part of the Fundamental Aeronautics program, researchers at NASA Glenn Research Center (GRC) are investigating new technologies supporting the development of lighter, quieter, and more efficient fans for turbomachinery applications. High performance fan blades designed to achieve such goals will be subjected to higher levels of aerodynamic excitations which could lead to more serious and complex vibration problems. Piezoelectric materials have been proposed as a means of decreasing engine blade vibration either through a passive damping scheme, or as part of an active vibration control system. For polymer matrix fiber composite blades, the piezoelectric elements could be embedded within the blade material, protecting the brittle piezoceramic material from the airflow and from debris. To investigate this idea, spin testing was performed on two General Electric Aviation (GE) subscale composite fan blades in the NASA GRC Dynamic Spin Rig Facility. The first bending mode (1B) was targeted for vibration control. Because these subscale blades are very thin, the piezoelectric material was surface-mounted on the blades. Three thin piezoelectric patches were applied to each blade — two actuator patches and one small sensor patch. These flexible macro-fiber-composite patches were placed in a location of high resonant strain for the 1B mode. The blades were tested up to 5000 rpm, with patches used as sensors, as excitation for the blade, and as part of open- and closed-loop vibration control. Results show that with a single actuator patch, active vibration control causes the damping ratio to increase from a baseline of 0.3% critical damping to about 1.0% damping at 0 RPM. As the rotor speed approaches 5000 RPM, the actively controlled blade damping ratio decreases to about 0.5% damping. This occurs primarily because of centrifugal blade stiffening, and can be observed by the decrease in the generalized electromechanical coupling with rotor speed.

scholarly journals Performance Characteristics of the Magnetic Constrained Layer Damping

2000 ◽  
Vol 7 (2) ◽  
pp. 81-90 ◽  
Author(s):  
A. Baz ◽  
S. Poh
Keyword(s):  
Permanent Magnets ◽  
Effective Means ◽  
Performance Characteristics ◽  
Structural Vibration ◽  
Constrained Layer Damping ◽  
Structural Vibrations ◽  
New Class ◽  
Elastic Layers ◽  
Damping Treatments ◽  
Passive Constrained Layer Damping

A new class of surface damping treatment is proposed to provide effective means for attenuating undesirable structural vibrations. The proposed treatment relies in its operation on the use of smart damping treatments which consist of integrated arrays of constrained visco-elastic damping layers that are controlled passively by a specially arranged network of permanent magnets. The interaction between the magnets and the visco-elastic layers aims at enhancing the energy dissipation characteristics of the damping treatments. In this manner, it would be possible to manufacture structures that are light in weight which are also capable of meeting strict constraints on structural vibration when subjected to unavoidable disturbances.Emphasis is placed here on introducing the concept and the basic performance characteristics of this new class of smart Magnetic Constrained Layer Damping (MCLD) treatments. Comparisons are also presented with conventional Passive Constrained Layer Damping (PCLD) in order to determine the merits and limitation of the MCLD treatments.

Quarter-Cycle Switching Control for Switch-Shunted Dampers

2004 ◽  
Vol 126 (2) ◽  
pp. 278-283 ◽  
Author(s):  
Gregg D. Larson ◽  
Kenneth A. Cunefare
Keyword(s):  
Vibration Control ◽  
Piezoelectric Materials ◽  
Active Vibration Control ◽  
Switching Control ◽  
Single Frequency ◽  
Effective Bandwidth ◽  
Control Logic ◽  
Resonant States ◽  
Active Vibration ◽  
Specific Implementation

Significant interest has been generated by the possibilities of active vibration control through the implementation of state switching, with a specific implementation embodied through piezoceramic shunting. A state-switched absorber (SSA) is a vibration absorber that has the unique ability to change its resonant state amongst multiple distinct resonant states while in motion, thereby increasing the effective bandwidth over that of a single frequency device and thereby allowing control of multi-frequency, transient, and time-varying disturbances. In contrast, a switch-shunted damper (SSD) is a variant of an SSA that is used to increase the damping of the structure to which the damper is applied. Active vibration control applications discussed in the literature indicate the potential advantages of SSDs which employ piezoelectric ceramics as switchable springs with control algorithms that require switching states at points of non-zero strain. However, consideration of the constitutive equations for piezoelectric materials indicates a discontinuity in the electrical and mechanical conditions imposed by switching the stiffness at non-zero strains. A prototype SSD has been built and tested to experimentally investigate switching control logic and electrical and mechanical discontinuities at switching points; experimental measurements with this prototype SSD indicate that quarter-cycle switching algorithms which include switching states at a condition of maximum strain yield enhanced damping effectiveness but also leads to the generation of potentially undesirable mechanical transients.

Experimental studies on active vibration control of smart plate using a modified PID controller with optimal orientation of piezoelectric actuator

2014 ◽  
Vol 22 (11) ◽  
pp. 2619-2631 ◽  
Author(s):  
Aleksandar M Simonović ◽  
Miroslav M Jovanović ◽  
Nebojša S Lukić ◽  
Nemanja D Zorić ◽  
Slobodan N Stupar ◽  
...  
Keyword(s):  
Vibration Control ◽  
Piezoelectric Actuator ◽  
Pid Controller ◽  
Active Vibration Control ◽  
Experimental Studies ◽  
Optimal Orientation ◽  
Active Vibration

Optimal Piezoelectric Sensors and Actuators Deployment for Active Vibration Suppression of Satellite Antenna Reflector

2012 ◽  
Vol 479-481 ◽  
pp. 1490-1494 ◽  
Author(s):  
Wen Bo Li ◽  
Xiao Ran Li ◽  
Zhi Gang Zhao ◽  
You Yi Wang ◽  
Yang Zhao
Keyword(s):  
Vibration Suppression ◽  
Piezoelectric Materials ◽  
Active Vibration Control ◽  
Antenna System ◽  
Gram Matrix ◽  
Linear Quadratic ◽  
Sensors And Actuators ◽  
Satellite Antenna ◽  
Active Vibration ◽  
Antenna Reflector

To solve the problem of active vibration control for satellite antenna reflector, which is weak damping and closely spaced modes, the optimal actuators/sensors deployment and controller designing need to be considered. Firstly, the optimal criterions of controllability and observability are designed according to the specificity of Gram Matrix eigenvalue in satellite antenna system equations. Secondly, based on the above criterions, piezoelectric materials (as sensors and actuators) and genetic algorithm are utilized to optimize the deployed locations of sensors and actuators. Finally, to suppress the vibration of satellite antenna reflector, a Linear Quadratic Gaussian (LQG) controller is designed under the impulse and white noise excitation respectively. The simulate results show the effectively deployed locations of sensors and actuators, and the correctness of designed LQG controller.

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