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

其应用重点是薄壁结构振动声学行为引起的声辐射的模拟。多层纤维增强复合材料和金属-塑料混杂复合材料的轻质结构具有高阻尼能力和高刚重比。这些部件的力学性能受到界面和局部不均匀性的影响，从而导致表征参数的不确定性和非线性。研究的重点是用有限元程序模拟变幅阻尼器。利用多项式混沌展开(GPC展开)的随机模型来考虑和实现不确定和局部变化的材料参数是该项目的另一个关键问题。要确定各材料参数的统计分布，必须有大量材料试验的大量数据基础。此外，实验结果对于验证所开发和扩展的模拟方法是必要的。研究项目的总体目标是将所有开发的模拟和实验方法应用于选定的薄壁零件，通过考虑显著的非线性和参数分布来提高确定声压级的精度。

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.