scholarly journals Experimental Active Vibration Control in Truss Structures Considering Uncertainties in System Parameters

2008 ◽  
Vol 2008 ◽  
pp. 1-14 ◽  
Author(s):  
Douglas Domingues Bueno ◽  
Clayton Rodrigo Marqui ◽  
Rodrigo Borges Santos ◽  
Camilo Mesquita Neto ◽  
Vicente Lopes
Keyword(s):  
Vibration Control ◽  
Dynamic Model ◽  
Electromechanical Coupling ◽  
Active Vibration Control ◽  
Experimental Methodology ◽  
Truss Structures ◽  
Linear Matrix ◽  
System Parameters ◽  
Identification Method ◽  
Active Vibration

This paper deals with the study of algorithms for robust active vibration control in flexible structures considering uncertainties in system parameters. It became an area of enormous interest, mainly due to the countless demands of optimal performance in mechanical systems as aircraft, aerospace, and automotive structures. An important and difficult problem for designing active vibration control is to get a representative dynamic model. Generally, this model can be obtained using finite element method (FEM) or an identification method using experimental data. Actuators and sensors may affect the dynamics properties of the structure, for instance, electromechanical coupling of piezoelectric material must be considered in FEM formulation for flexible and lightly damping structure. The nonlinearities and uncertainties involved in these structures make it a difficult task, mainly for complex structures as spatial truss structures. On the other hand, by using an identification method, it is possible to obtain the dynamic model represented through a state space realization considering this coupling. This paper proposes an experimental methodology for vibration control in a 3D truss structure using PZT wafer stacks and a robust control algorithm solved by linear matrix inequalities.

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.

Influence of piezoelectric nonlinearity on active vibration suppression of smart laminated shells using strong field actuation

2016 ◽  
Vol 24 (3) ◽  
pp. 505-526 ◽  
Author(s):  
M Yaqoob Yasin ◽  
Santosh Kapuria
Keyword(s):  
Vibration Control ◽  
Feedback Linearization ◽  
Electromechanical Coupling ◽  
Strong Field ◽  
Active Vibration Control ◽  
Constitutive Relationship ◽  
Radius Of Curvature ◽  
Control Input ◽  
Laminated Shells ◽  
Active Vibration

In this work, we study the effect of piezoelectric nonlinearity on shape and active vibration control of smart piezolaminated composite and sandwich shallow shells under strong field actuation. An efficient finite element model with advanced laminate kinematics and full electromechanical coupling is developed for this purpose. The nonlinearity is modeled using a rotationally invariant quadratic constitutive relationship for the piezoelectric material. For the laminate kinematics, a recently developed efficient layerwise theory, which is computationally as efficient as an equivalent single-layer theory, and has been shown to yield very accurate results in comparison with three-dimensional piezoelasticity based solutions for linear electromechanical response of hybrid laminated shells, has been employed. The nonlinear static response for shape control is obtained using the direct iteration method, and the active vibration control response with linear quadratic Gaussian controller is obtained by using the feedback linearization approach through control input transformation. It is shown that the linear model significantly overestimates the voltage required for shape or vibration control, when the applied electric field is beyond the threshold limit of the actuator. Thus, the use of the nonlinear model is essential for designing the control system utilizing the full actuation authority of the actuators. The effects of actuator thickness, radius of curvature to span ratio and applied loading on the relative difference between linear and nonlinear predictions are illustrated for shape and vibration control of smart cylindrical and spherical shells.

Substructuring Dynamic Modeling and Active Vibration Control of a Smart Parallel Platform

2004 ◽  
Author(s):  
Xiaoyun Wang ◽  
James K. Mills
Keyword(s):  
Vibration Control ◽  
Dynamic Model ◽  
Motion Control ◽  
Dynamic Models ◽  
Active Vibration Control ◽  
System Dynamic ◽  
Control Law ◽  
Active Vibration ◽  
Parallel Platform ◽  
Simulation Results

A substructuring approach to derive dynamic models for closed-loop mechanisms is applied to model a flexible-link planar parallel platform with Lead Zirconate Titanate (PZT) transducers. The Lagrangian Finite Element (FE) formulation is used to model flexible linkages, in which translational and rotary degrees of freedom exist. Craig-Bampton mode sets are extracted from these FE models and then used to assemble the dynamic model of the planar parallel platform through the application of Lagrange’s equation and the Lagrange multiplier method. Electromechanical coupling models of surface-bonded PZT transducers with the host flexible linkages are introduced to the reduced order dynamic models of flexible linkages. The assembled system dynamic model with moderate model order can represent essential system dynamic behavior and maintain kinematic relationships of the planar parallel platform. A Proportional, Integral, and Derivative (PID) control law is used as the motion control law. Strain rate feedback (SRF) active vibration control is selected as the vibration control law. Motion control simulation results with active vibration control and simulation results without active vibration control are compared. The comparison shows the effectiveness of active vibration control.

scholarly journals Active Piezoelectric Vibration Control of Subscale Composite Fan Blades

2012 ◽  
Vol 135 (1) ◽  
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.

Dynamic model and active vibration control of a membrane antenna structure

2017 ◽  
Vol 24 (18) ◽  
pp. 4282-4296 ◽  
Author(s):  
Xiang Liu ◽  
Guoping Cai ◽  
Fujun Peng ◽  
Hua Zhang
Keyword(s):  
Vibration Control ◽  
Dynamic Model ◽  
Active Vibration Control ◽  
Piezoelectric Actuators ◽  
Dynamic Responses ◽  
Linear Quadratic ◽  
Particle Swarm Optimizer ◽  
Control Cost ◽  
Antenna Structure ◽  
Active Vibration

This paper studies a dynamic model and active vibration control of a membrane antenna structure. Based on the finite element method (FEM), the dynamic model of the membrane antenna structure is established. Piezoelectric actuators are used to suppress the vibration of the structure and their optimal locations on the membrane are determined using the optimization method, where an efficient numerical criterion depended on controllability Grammian is used as optimization criterion and the particle swarm optimizer (PSO) is used as optimization algorithm. Active controllers are designed by the classical linear quadratic regulator (LQR) method. Simulation results indicate that the vibration modes and dynamic responses obtained by the dynamic model established in this paper coincide well with the results of the software ABAQUS; vibration of the structure can be suppressed effectively by the piezoelectric actuators, and optimal placed actuators not only can produce better control effectiveness but also need smaller control cost.

Pole Placement Techniques for Active Vibration Control of Smart Structures: A Feasibility Study

2007 ◽  
Vol 129 (5) ◽  
pp. 601-615 ◽  
Author(s):  
Rajiv Kumar ◽  
Moinuddin Khan
Keyword(s):  
Vibration Control ◽  
Closed Loop ◽  
Smart Structures ◽  
Active Vibration Control ◽  
Control Design ◽  
Pole Placement ◽  
Parametric Uncertainties ◽  
Robust Performance ◽  
System Parameters ◽  
Active Vibration

It is well known that there is degradation in the performance of a fixed parameter controller when the system parameters are subjected to a change. Conventional controllers can become even unstable, with these parametric uncertainties. This problem can be avoided by using robust and adaptive control design techniques. However, to obtain robust performance, it is desirable that the closed-loop poles of the perturbed structural system remain at prespecified locations for a range of system parameters. With the aim to obtain robust performance by manipulating the closed loop poles of the perturbed system, feasibility of the pole placement based controller design techniques is checked for active vibration control applications. The controllers based on the adaptive and robust pole placement method are implemented on smart structures. It was observed that the adaptive pole placement controllers are noise tolerant, but require high actuator voltages to maintain stability. However, robust pole placement controllers require comparatively small amplitude of control voltage to maintain stability, but are noise sensitive. It was realized that by using these techniques, robust stability and performance can be obtained for a moderate range of parametric uncertainties. However, the position of closed-loop poles should be judiciously chosen for both the control design strategies to maintain stability.

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