Synchronized Switched Shunt Control Technique Applied on a Cantilevered Beam: Numerical and Experimental Investigations

2008 ◽  
Vol 19 (9) ◽  
pp. 1089-1100 ◽  
Author(s):  
Monica Ciminello ◽  
Antonio Calabrò ◽  
Salvatore Ameduri ◽  
Antonio Concilio
Keyword(s):  
Control Technique ◽  
Experimental Investigations ◽  
Cantilevered Beam ◽  
Shunt Control

A Wireless Vibration Control Technique for Gas Turbine Blades Using Piezoelectric Plates and Contactless Energy Transfer

2013 ◽  
Author(s):  
Fabio Botta ◽  
Nigel Marx ◽  
Christoph Schwingshackl ◽  
Giovanni Cerri ◽  
Daniele Dini
Keyword(s):  
Finite Elements ◽  
Vibration Control ◽  
Gas Turbine ◽  
Control Technique ◽  
Experimental Investigations ◽  
Rotating Beam ◽  
Optimal Position ◽  
Experimental Apparatus ◽  
Piezoelectric Elements ◽  
Piezoelectric Plates

Gas turbine blade vibrations can give rise to catastrophic failures, and cause a reduction of the blades’ life due to fatigue-related phenomena. Damping is often required to improve performance of bladed disks. Recently, the adoption of piezoelectric elements has received considerable attention by many researchers for potential applicability in different areas of mechanical, aerospace, aeronautical and civil engineering. Furthermore, studies of blades’ vibration-control via piezoelectric plates are beginning to appear. In previous contributions, the authors have proposed a model to control multimode beam vibrations using piezoelectric elements. Analytical results have been validated through comparison with the results of a multi-physics finite elements package (COMSOL), as well as with data available in the literature. Experimental investigations carried out by the authors using a cantilever beam support the proposed theory. The model defines the optimal position of the plates to damp the multimode vibrations. Different loading scenarios where different modes were excited with different percentages were considered [1]. This model has also been extended to a rotating beam, and a finite elements code has been used to obtain the optimal position of the piezo-plates at different rotating speeds ([4]). In this paper the authors report the first results of the experimental investigations performed using a rotating beam. An experimental apparatus has been designed and constructed, including a new wireless power transfer system to eliminate issues associated with the use of slip rings. A Matlab program has been developed to control the system and interpret the data. Also, a laser pointing system has been used to measure the vibrations of a single blade and, thus, the effectiveness of the system. The preliminary results obtained using the newly developed test rig are discussed after presenting the experimental setup and the acquisition system designed and implemented by the authors.

scholarly journals Simultaneous Structural Health Monitoring and Vibration Control of Adaptive Structures Using Smart Materials

2002 ◽  
Vol 9 (6) ◽  
pp. 329-339 ◽  
Author(s):  
Myung-Hyun Kim
Keyword(s):  
Vibration Control ◽  
Monitoring System ◽  
Health Monitoring ◽  
Smart Materials ◽  
Vibration Suppression ◽  
Sliding Mode ◽  
Structural Vibration ◽  
Control Technique ◽  
Experimental Investigations ◽  
Health Monitoring System

The integration of actuators and sensors using smart materials enabled various applications including health monitoring and structural vibration control. In this study, a robust control technique is designed and implemented in order to reduce vibration of an active structure. Special attention is given to eliminating the possibility of interaction between the health monitoring system and the control system. Exploiting the disturbance decoupling characteristic of the sliding mode observer, it is demonstrated that the proposed observer can eliminate the possible high frequency excitation from the health monitoring system. At the same time, a damage identification scheme, which tracks the changes of mechanical impedance due to the presence of damage, has been applied to assess the health condition of structures. The main objective of this paper is to examine the potential of combining the two emerging techniques together. Using the collocated piezoelectric sensors/actuators for vibration suppression as well as for health monitoring, this technique enabled to reduce the number of system components, while enhancing the performance of structures. As an initial study, both simulation and experimental investigations were performed for an active beam structure. The results show that this integrated technique can provide substantial vibration reductions, while detecting damage on the structure at the same time.

Experimental investigations of the use of cartilage in tympanic membrane reconstruction

2000 ◽  
Vol 21 (3) ◽  
pp. 322-328 ◽  
Author(s):  
T ZAHNERT ◽  
K HUTTENBRINK ◽  
D MURBE ◽  
M BORNITZ
Keyword(s):  
Tympanic Membrane ◽  
Experimental Investigations

EXPERIMENTAL INVESTIGATIONS OF THE QUANTUM PHOTOVOLTAIC EFFECT IN InAs-GaSb SEMICONDUCTOR SUPERLATTICES

1987 ◽  
Vol 48 (C5) ◽  
pp. C5-183-C5-186
Author(s):  
J. BLEUSE ◽  
P. VOISIN ◽  
M. VOOS ◽  
L. L. CHANG ◽  
L. ESAKI
Keyword(s):  
Photovoltaic Effect ◽  
Experimental Investigations ◽  
Semiconductor Superlattices

Evaluation of the accuracy of reconstruction of the electrophysical and geometric parameters of multilayer dielectric coatings by the multi-frequency radio wave method of a slow surface electromagnetic waves

2020 ◽  
pp. 51-58
Author(s):  
Aleksandr I. Kazmin ◽  
Pavel A. Fedjunin
Keyword(s):  
Radio Wave ◽  
Noise Level ◽  
Electromagnetic Waves ◽  
Dielectric Materials ◽  
Geometric Parameters ◽  
Experimental Investigations ◽  
Wave Method ◽  
Dielectric Coatings ◽  
Surface Electromagnetic Waves ◽  
Multilayer Dielectric

One of the most important diagnostic problems multilayer dielectric materials and coatings is the development of methods for quantitative interpretation of the checkout results their electrophysical and geometric parameters. The results of a study of the potential informativeness of the multi-frequency radio wave method of surface electromagnetic waves during reconstruction of the electrophysical and geometric parameters of multilayer dielectric coatings are presented. The simulation model is presented that makes it possible to evaluate of the accuracy of reconstruction of the electrophysical and geometric parameters of multilayer dielectric coatings. The model takes into account the values of the electrophysical and geometric parameters of the coating, the noise level in the measurement data and the measurement bandwidth. The results of simulation and experimental investigations of reconstruction of the structure of relative permittivitties and thicknesses of single-layer and double-layer dielectric coatings with different thicknesses, with different values of the standard deviation (RMS) of the noise level in the measured attenuation coefficients of the surface slow electromagnetic wave are presented. Coatings based on the following materials were investigated: polymethyl methacrylate, F-4D PTFE, RO3010. The accuracy of reconstruction of the electrophysical parameters of the layers decreases with an increase in the number of evaluated parameters and an increase in the noise level. The accuracy of the estimates of the electrophysical parameters of the layers also decreases with a decrease in their relative permittivity and thickness. The results of experimental studies confirm the adequacy of the developed simulation model. The presented model allows for a specific measuring complex that implements the multi-frequency radio wave method of surface electromagnetic waves, to quantify the potential possibilities for the accuracy of reconstruction of the electrophysical and geometric parameters of multilayer dielectric materials and coatings. Experimental investigations and simulation results of a multilayer dielectric coating demonstrated the theoretical capabilities gained relative error permittivity and thickness of the individual layers with relative error not greater than 10 %, with a measurement bandwidth of 1 GHz and RMS of noise level 0,003–0,004.

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