Sound emission of multi-layer composites with non-linear and local varying damping properties

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The application is focused on the simulation of sound radiation caused by the vibro-acoustic behaviour of thin-walled structures. Lightweight structures of multi-layer fibre reinforced composites and hybrid metal-plastic composites offer high damping capabilities and a high stiffness-weight ratio. The mechanical properties of such components are influenced by interfaces and local inhomogeneities resulting in uncertainties and non-linearities of the characterising parameters. The investigations are focused on the simulation of amplitude depending damping by finite-element procedures. Consideration and implementation of uncertain and locally varying material parameters with the help of a stochastic model using polynomial chaos expansions (gPC-expansions) accounts for another key issue of the project. The prerequisite, a large data basis of extensive material tests is necessary for the identification of the statistic distribution of each material parameter. Furthermore, the experimental results are essential for the verification of the developed and extended simulation methods. The general aim of the research project consists in the application of all developed simulation and experimental methods on a chosen thin-walled work piece increasing the accuracy of the determined sound pressure levels by the consideration of significant non-linearities and parameter distributions.