Active Control of Radiated Sound With Integrated Piezoelectric Composite Structures. Volume 2 Appendices (Concl.)
Abstract
The report describes work by MRL-PSU on developing an constructing a new actuator called PANEL based upon using double amplification obtained from a system of orthogonal bimorph piezoelectric elements covered with an acoustic diaphragm configured in a flextensional type manner. The resultant PANEL source after many iterations of analysis, development, construction and testing was found to provide amplification ratios of around 250:1 and generate diaphragm vibration levels of the order of 500 microns (on resonance) and 200 microns (off resonance) over a frequency range of o to 1500Hz. The corresponding sound pressure levels generated by the PANEL source at im ranged from 80dB at 200Hz to 90dB above 400Hz. These performance levels were considered high enough to enable the PANEL source to be applied to a number of practical noise problems such as interior noise in aircraft and cars as well as electrical transformer noise and jet engine inlet noise. For applications below 200Hz, where the performance of the PANEL falls off, a new pseudo-shear multi-layer actuator utilizing folded multi-layer piezoelectric elements was developed and tested. The new pseudo- shear actuator was found to have significantly enhanced very low frequency performance below 200Hz. The report also describes the new active noise control approach based upon implementing an active-skin which completely covers the structure conceived by VAL- VPI. In the VAL part of the project, multiple PANEL actuators were integrated into a continuous skin system with independently controllable sections.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 06, 1998
- Accession Number
- ADA356904
Entities
People
- Christopher R. Fuller
- L. E. Cross
Organizations
- Virginia Tech