Experimental verification of vibration absorbers combined with input shaping for oscillatory systems

2004 ◽  
Author(s):  
J. Brogan ◽  
J. Fortgang ◽  
W. Singhose
Keyword(s):  
Experimental Verification ◽  
Input Shaping ◽  
Vibration Absorbers ◽  
Oscillatory Systems

Concurrent Design of Vibration Absorbers and Input Shapers

2004 ◽  
Vol 127 (3) ◽  
pp. 329-335 ◽  
Author(s):  
Joel Fortgang ◽  
William Singhose
Keyword(s):  
Feedback Control ◽  
Computer Simulations ◽  
Performance Feedback ◽  
High Performance ◽  
Experimental Results ◽  
Input Shaping ◽  
Concurrent Design ◽  
Vibration Absorbers ◽  
External Disturbances

Systems with flexible dynamics often vibrate due to external disturbances, as well as from changes in the reference command. Feedback control is an obvious choice to deal with these vibrations, but in many cases, it is insufficient or difficult to implement. A technique that does not rely on high performance feedback control is presented here. It utilizes a combination of vibration absorbers and input shapers. Vibration absorbers have been used extensively to reduce vibration from sinusoidal disturbances, but they can also be implemented to reduce the response from transient functions. Input shaping has proven beneficial for reducing vibration that is caused by changes in the reference command. However, input shaping does not deal with vibration excited by external disturbances. In this paper, vibration absorbers and input shapers are designed sequentially and concurrently to reduce vibration from both the reference command and from external disturbances. The usefulness of this approach is demonstrated through computer simulations and experimental results.

Optimal Placement of Piezoelectric Transducers for Passive Vibration Control of Geometrically Non-Linear Structures

Aerospace ◽  
2004 ◽  
Author(s):  
Suresh V. Venna ◽  
Y. J. Lin
Keyword(s):  
Vibration Control ◽  
Experimental Verification ◽  
Electric Potential ◽  
Leading Edge ◽  
Piezoelectric Transducers ◽  
Vibration Absorbers ◽  
Passive Vibration Control ◽  
Edge Structure ◽  
Piezoelectric Elements ◽  
Piezoelectric Vibration

In this paper, an attempt is made to determine optimal location of piezoelectric transducers for passive vibration control of geometrically complicated structures and shells with non-linear curvatures. Industry-standard aircraft leading edge structure is considered for the analysis and experimental verification. Finite element model of the leading edge structure consisting of a thin layer of piezoelectric elements on the inner surface of the leading edge covering the whole surface is built and appropriate boundary conditions are applied. All the piezoelectric properties are incorporated into the elements. Modal piezoelectric analysis is performed to investigate the electric potential developed in the piezoelectric elements in the first bending and torsion modes. Location of the piezoelectric elements yielding highest amount of electric potential is identified as the best location for vibration absorption. Based on the analysis results, six piezoelectric vibration absorbers are determined to be used for performing the passive vibration control of the two modes. Results of the analysis are verified with an experimental testing of the aluminum leading edge with piezoelectric vibration absorbers firmly attached to it. A good agreement is found between the analytical and experimental results. Further, two resistive shunt circuits are designed for the passive damping of the first bending and torsion modes in which the electric potential developed would be dissipated as heat to obtain passive vibration compensation. Experimental verification of the passive damping is performed at these two modes with appropriate shunt circuits affixed to the piezoelectric vibration absorbers. Amplitude reduction around 30% and 25% and Q-factor reduction up to 15% and 10% are obtained in the bending and torsion modes, respectively. In addition, some amount of damping is observed at higher modes as well.

Sign in / Sign up

Export Citation Format

Share Document