Tuned vibration absorbers (TVAs) are spring-mass-damper devices used to mini-mize energy in a vibrating body. TVAs decrease in efficiency when the vibrating body is
subjected to variable, broadband, or random excitation. A state-switched absorber (SSA)
can be used in these variable, broadband, or random excitation cases to more effectively
reduce excitation. An SSA is a mass-spring-damper where one or more of these elements can instantaneously and discretely change. An SSA was designed, built and tested to fit the
specifications for TVAs found on ATR 72 and 42 airplane fuselages. A magnetorheological
elastomer (MRE), an elastomer with imbedded iron particles, was selected as a variable
spring. Flux lines concentrated through all MREs in absorber configurations. MREs containing
35% iron by volume yielded the largest frequency shift. A 35% MRE based absorber had a frequency range of 45-183 Hz, which corresponds to a 360% frequency increase. Transient absorber behavior was observed by recording rise and drop times to step field intensity changes.The 35% MRE absorber yielded a 0.20 second rise time and a 0.03 second drop time. Future work will determine whether a modified input signal can generate an appropriate
transient response.
| Identifer | oai:union.ndltd.org:GATECH/oai:smartech.gatech.edu:1853/7143 |
| Date | 08 June 2005 |
| Creators | Lerner, Anne-Marie Albanese |
| Publisher | Georgia Institute of Technology |
| Source Sets | Georgia Tech Electronic Thesis and Dissertation Archive |
| Language | en_US |
| Detected Language | English |
| Type | Thesis |
| Format | 2342008 bytes, application/pdf |
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