438 - A detailed evaluation of analytical, numerical and experimental methods for a smart piezoelectric beam in a higher frequency range
Dennerlein J., Köppe H., Nunninger S., Bechtold M., Gabbert U.
Abstract
In the design of smart structures analytical models can contribute to a better understanding of the structural behaviour as well as to the development of advanced numerical analysis and simulation tools, such as the finite element method. Since analytical models are restricted to simple structures a clamped beam attached with piezoelectric patches was selected as functional demonstrator. The patches act as sensors and actuators in a collocated and non-collocated manner. Analytical, numerical und experimental methods have been applied to investigate the vibration behaviour in detail to get a deeper insight in the behaviour of smart structures. Structure and experimental set-up are described first. Then the approaches to model and to simulate the active beam are presented. In the analytical analysis an Euler-Bernoulli model is used. The actuator influence on a collocated sensor is modelled by a feedthrough factor. Modal damping is determined by measured frequency transfer functions (FRFs).Then the finite element modelling is presented, based on 3D finite elements including the patches with their fully coupled electromechanical fields. The FE-software COSAR was used to carry out the simulations as well as the calculation of the FRFs. It is shown that the analytical FRFs are in a good agreement with the numerically simulated ones. The results are verified with experimental data in a frequency range up to 5 kHz including the first 10 bending modes. The observed differences between simulated and measured bending mode eigenfrequencies are less than 1% and the average error in amplitude is less than 1dB for collocated patch configurations. Further results will be discussed in detail in the paper. Finally it can be concluded that a beam is sufficiently complex to develop a thorough understanding of the main behaviour of smart structures. Based on the presented analytical FRFs further investigations regarding patch placement and compensator development are under progress.
Citation
Dennerlein J.; Köppe H.; Nunninger S.; Bechtold M.; Gabbert U.: A detailed evaluation of analytical, numerical and experimental methods for a smart piezoelectric beam in a higher frequency range, CD-ROM Proceedings of the Thirtheenth International Congress on Sound and Vibration (ICSV13), July 2-6, 2006, Vienna, Austria, Eds.: Eberhardsteiner, J.; Mang, H.A.; Waubke, H., Publisher: Vienna University of Technology, Austria, ISBN: 3-9501554-5-7
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