Applied Vibration Suppression Using Piezoelectric Materials

Applied Vibration Suppression Using Piezoelectric Materials
Author: Mehrdad R. Kermani
Publisher: Nova Publishers
Total Pages: 194
Release: 2008
Genre: Science
ISBN: 9781600218965

The aim of this book is to provide insight on the vibration problem in structurally flexible mechanisms, particularly robotic manipulators. The book covers different aspects of flexible structures. It partially includes the fundamental formulations for modelling of a flexible structure actuated with piezoelectric actuators. Mathematical modelling, when possible, as well as experimental techniques for obtaining models of flexible structures are discussed. Additionally, different control techniques adapted for flexible robotic manipulators equipped with piezoelectric actuators and sensors are covered in the book. Depending on the system, linear and non-linear control techniques for stabilising residual vibrations in the system are discussed.

Actively Controlling Buffet-Induced Excitations

Actively Controlling Buffet-Induced Excitations
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
Total Pages: 26
Release: 2018-06-24
Genre:
ISBN: 9781721790449

High performance aircraft, especially those with twin vertical tails, encounter unsteady buffet loads when flying at high angles of attack. These loads result in significant random stresses, which may cause fatigue damage leading to restricted capabilities and availability of the aircraft. An international collaborative research activity among Australia, Canada and the United States, conducted under the auspices of The Technical Cooperation Program (TTCP) contributed resources toward a program that coalesced a broad range of technical knowledge and expertise into a single investigation to demonstrate the enhanced performance and capability of the advanced active BLA control system in preparation for a flight test demonstration. The research team investigated the use of active structural control to alleviate the damaging structural response to these loads by applying advanced directional piezoelectric actuators, the aircraft rudder, switch mode amplifiers, and advanced control strategies on an F/A-18 aircraft empennage. Some results of the full-scale investigation are presented herein. Moses, Robert W. and Pototzky, Anthony S. and Henderson, Douglas A. and Galea, Stephen C. and Manokaran, Donald S. and Zimcik, David G. and Wickramasinghe, Viresh and Pitt, Dale M. and Gamble, Michael A. Langley Research Center RTO-MP-AVT-123

Progress and New Techniques in Buffet Alleviation

Progress and New Techniques in Buffet Alleviation
Author:
Publisher:
Total Pages: 0
Release: 1997
Genre:
ISBN:

Research for twin-tail buffet alleviation is centered on ground tests, wind tunnel tests, and computational fluid dynamics (CFD) analysis. The objective of the research is to improve present technology to obtain a significant reduction in vibration due to buffet. One of the techniques for active control of buffet is the use of smart structures with piezoelectric actuators. The actuators are embedded in the vertical tails in the most advantageous locations to reduce the response of the various structural modes of vibration due to buffet excitation. Ground and wind tunnel tests are necessary to ascertain the piezoelectric actuator's authority at full loads. It is also necessary to evaluate the increase in weight compared with the increase in damping. The results using two different types of piezoelectric actuators are encouraging. In-house wind tunnel tests on a 4.7% scale model of an F-15C aircraft were also conducted to ascertain the effects of tangential blowing and piezoelectric actuators. The tests were performed in the SARL (Subsonic Aerodynamics Research Laboratory) wind tunnel. Tangential blowing had some effect at lower angles of attack. A numerical investigation was conducted simultaneously. This report presents an overview of the buffet research at various organizations, results of the in-house wind tunnel test, and a summary of the computational effort.