Brink, Maarten Cornelis
Transient finite element simulations and experiments on active control of sound transmission loss through plates.
Technische Universität, Darmstadt
[Ph.D. Thesis], (2008)
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|Item Type:||Ph.D. Thesis|
|Title:||Transient finite element simulations and experiments on active control of sound transmission loss through plates|
In this thesis the sound transmission loss of a plate has been investigated. It serves as an abstract model for the noise barrier between engine and passengers in a bus. A finite element simulation model has been developed to be able to predict the plate's noise reduction effect. To increase this reduction without adding too much mass, the integration of active noise control (ANC) has been investigated. The active system contained a controller, microphones and piezoelectric actuators. The influence of this system on the plate's transmission loss has been determined for three noise types: random noise, tonal noise and sweep function. The transient character of the simulations allows the possibility of directly integrating the ANC algorithm with corresponding sensors and actuators into the simulation model. For that, all controller tasks including sample rate changes and anti-aliasing filtering are included in the simulation algorithm. Doing so, the ANC's critical adaptation phase can be investigated during the simulations. Configuration changes can be tested before the actual noise barrier is built. The ANC experiments showed very good reduction for the tonal noise and good reduction for the sweep noise. This reduction could be increased even more if the used controller would allow more channels. Due to the stochastic character the reduction of random noise was lower; here only the highest peaks could be reduced. The passive and active simulations were in reasonable agreement with the experimental results. They showed that this simulation approach allows an optimisation of the system before it is constructed and tested experimentally.
|Place of Publication:||Darmstadt|
|Uncontrolled Keywords:||transmission loss, active noise control, active structural acoustic control, finite element method, computer simulation|
|Classification DDC:||600 Technik, Medizin, angewandte Wissenschaften > 620 Ingenieurwissenschaften|
|Divisions:||16 Fachbereich Maschinenbau|
|Date Deposited:||17 Oct 2008 09:22|
|Last Modified:||07 Dec 2012 11:53|
|Referees:||Hanselka, Prof. Dr.- Holger and Nordmann, Prof. Dr.- Rainer|
|Advisors:||Hanselka, Prof. Dr.- Holger|
|Refereed:||23 January 2008|