Analytical and Experimental Investigations of the Active Stiffener Concept for Shape Control of a Circular Plate Structure

2003 ◽  
Author(s):  
Michael Philen ◽  
Kon-Well Wang
Keyword(s):  
Circular Plate ◽  
Shape Control ◽  
Experimental Investigations ◽  
Plate Structure

Active Stiffener Actuators for High-Precision Shape Control of Circular Plate Structure

AIAA Journal ◽  
2004 ◽  
Vol 42 (12) ◽  
pp. 2570-2578 ◽  
Author(s):  
Michael K. Philen ◽  
K. W. Wang
Keyword(s):  
Circular Plate ◽  
High Precision ◽  
Shape Control ◽  
Plate Structure

Active Stiffeners for Vibration Control of a Circular Plate Structure: Analytical and Experimental Investigations

2005 ◽  
Vol 127 (5) ◽  
pp. 441-450 ◽  
Author(s):  
Michael K. Philen ◽  
K. W. Wang
Keyword(s):  
Vibration Control ◽  
Circular Plate ◽  
Adaptive Optics ◽  
Shape Control ◽  
Extended Period ◽  
Surface Shape ◽  
Experimental Investigations ◽  
Weight Restrictions ◽  
Plate Shape ◽  
Stringent Performance

Space-based adaptive optic systems have gained considerable attention within the past couple of decades. Achieving the increasingly stringent performance requirements for these systems is greatly hindered by strict weight restrictions, size limitations, and subjected hostile environments. There has been considerable attention in developing lightweight adaptive optics where piezoelectric sheet actuators are attached on the back of optical mirrors to achieve a high precision surface shape with minimum additional weight. Vibration control of such large flexible space structures is continually challenging to engineers due to the large number of actuators and sensors and the large number of vibration modes within the operational bandwidth. For these structures, any disturbed modes are likely to remain vibrating for an extended period of time due to the small amount of damping available. As a result, controller spillover should be minimized as much as possible to avoid exciting the residual modes. In recent investigations of circular plate shape control by [Philen and Wang, Int. Soc. Opt. Eng. 4327, pp. 709–719]. It was demonstrated that directional decoupling of the two-dimensional actuator (meaning that the actuation in one of the two directions is eliminated) improves the system performance when correcting for the lower order Zernike static deformations. This directional decoupling effect can be achieved through an active stiffener (AS) design. In this research, analytical and experimental efforts are carried out to examine the effect of the active stiffener actuators in reducing the controller spillover through the stiffeners’ decoupling characteristics. It is shown that significant reductions in controller spillover can be achieved in systems using the active stiffener actuators when compared to systems having direct attached (DA) actuators, thus resulting in improved vibration control performance. The experimental results verify the analytical predictions and clearly demonstrate the merit of the active stiffener concept.

Experimental investigations of hypervelocity impact onto aluminium dual-plate structure

1992 ◽  
Vol 8 (4) ◽  
pp. 374-382 ◽  
Author(s):  
Zhang Deliang ◽  
Tan Qingming ◽  
Zhao Chengxiu ◽  
Yang Yemin ◽  
Ge Xuezhen ◽  
...  
Keyword(s):  
Hypervelocity Impact ◽  
Experimental Investigations ◽  
Plate Structure ◽  
Dual Plate

scholarly journals Subsonic Flutter of Cantilever Rectangular PC Plate Structure

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Kemal Yaman
Keyword(s):  
Wind Tunnel ◽  
Modal Analysis ◽  
Simple Structure ◽  
Experimental Investigations ◽  
Flexible Plate ◽  
Test Results ◽  
Plate Structure ◽  
Flutter Analysis ◽  
Solution Methods ◽  
Subsonic Flutter

Flutter characteristics of cantilever rectangular flexible plate structure under incompressible flow regime are investigated by comparing the results of commercial flutter analysis program ZAERO©with wind tunnel tests conducted in Ankara Wind Tunnel (ART). A rectangular polycarbonate (PC) plate, 5 × 125 × 1000 mm in dimension, is used for both numerical and experimental investigations. Analysis and test results are very compatible with each other. A comparison between two different solution methods (g-methodandk-method) of ZAERO©is also done. It is seen that thek-methodgives a closer result than the other one. However,g-method results are on a conservative side and it is better to use conservative results, namely,g-method results. Even if the modal analysis results are used for the flutter analysis for this simple structure, a modal test should be conducted in order to validate the modal analysis results to have accurate flutter analysis results for more complicated structures.

Active Stiffener Concept for Shape Control of Two Dimensional Structures

2002 ◽  
Author(s):  
Michael Philen ◽  
Kon-Well Wang
Keyword(s):  
Piezoelectric Ceramic ◽  
Shape Control ◽  
Electromechanical Coupling ◽  
Element Model ◽  
Optimal Placement ◽  
Two Dimensional ◽  
Plate Structure ◽  
Transmitted Force ◽  
Host Structure ◽  
Multiple Actuators

A substantial amount of research exists concerning shape and vibration control of structures with attached piezoelectric ceramic sheet actuators. Researchers have investigated the optimal placement, size, and electrode pattern of these piezoceramic actuators to maximize the performance of the system. In many situations, the performance could be further improved with tailoring of the electromechanical properties of the actuator. For example, it was found that to avoid exciting higher order modes, the ideal actuator would be one that only actuates in one direction when controlling certain modes in a two-dimensional plate structure [1]. As known, the 31 and 32 electromechanical coupling values of a piezoelectric ceramic patch poled in the 3 direction is equal. Therefore to achieve decoupling of the actuator action in the 31 and 32 directions, a mechanism is required. In this paper, an active stiffener concept is proposed to realize such an effect where a stiffener is inserted between a host structure and the piezoelectric ceramic actuator patch. Using a solid finite element model, an analysis of a single active stiffener attached to a rigid and a flexible host structure is presented. In the analysis, the effects of various material and system parameters on the transmitted force to the structure are presented. It is seen that the active stiffener can significantly reduce the transmitted force in the selected direction. The performance of the active stiffener concept with multiple actuators is presented for controlling the shape of a large flexible circular plate structure.

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