Experimentelle Untersuchung einer Platte und einer einfachen Doppelschale mit applizierten Dämpfungspaketen

Abstract

For active control purposes a double wall structure enables the measurement of a time advanced reference signal for a feedforward system because the reference signal can be measured at the primary panel and the control system can be applied to the second panel. In aerospace engineering these double wall sections are often filled with absorbent materials. These materials have an influence on the structural dynamics of the double wall section. In order to guarantee the function of the feedforward control system the damped double wall section has to show a linear system behavior. In order to analyze the linearity of double wall panels with different absorbent materials this study experimentally investigates different damping concepts on a simple double wall structure. The double wall structure is a buildup with two 0.8 x 0.6 m² aluminum plates and different damping concepts are applied to the cavity between. The absorbent material is added to the secondary panel where glass wool in different configurations or constraint layer damping is applied. The linear system behavior up to 500 Hz can be verified with the coherence function for all concepts. Above 500 Hz it can be shown that the test set-up has a substantial effect on the dynamics of the double wall section.