A combined numerical-experimental approach for the damping evaluation of nonlinear dissipative vibration systems

机械结构的动力学本质上受阻尼量的影响，阻尼可能具有非常不同的物理性质。除了材料阻尼之外，还包括螺栓和法兰等摩擦接头、颗粒阻尼器、压电阻尼器等等。然而，阻尼值的准确预测仍然是一个悬而未决的问题。因此，在这个项目中，将开发一种方法，该方法将基于对简单非线性代理模型的调查，由适当的模型简化技术产生。不同的非线性阻尼原理可以用所谓的非线性能量汇（NES）来表示，它们局部附着在主体结构上。特别注意对所得到的非线性替代模型的求解，应用了延拓法、分岔法、交变频率-时间法、多谐法和稳定性分析等方法。作为主要成果，研究结果将深入了解非线性阻尼装置的效率，特别是鲁棒性，以便评估它们对具有不确定参数和不同操作条件的结构的适用性。数值研究将伴随着实验来验证方法。

The dynamics of mechanical structures is essentially affected by the amount of damping, which may be of very different physical nature. Beside material damping these are e.g. in frictional joints such as bolts and flanges, particle dampers, piezo damping and much more. However, the accurate prediction of the damping values still is an open issue. Hence, in this project, a methodology will be developed that is based on the investigation of simple nonlinear surrogate models, resulting from appropriate model reduction techniques. Different nonlinear damping principles may be represented by so-called nonlinear energy sinks (NES) that are attached locally to the host structure. Special attention is paid on the solution of the obtained nonlinear surrogate models, applying procedures like continuation methods, bifurcation analysis, alternating frequency-time-methods, multiharmonic approaches and stability analysis. As a main outcome, the results will give insight in the efficiency and, in particular, the robustness of nonlinear damping devices, in order to evaluate their applicability to structures with uncertain parameters and varying operating conditions. The numerical studies will be accompanied by experiments to validate the methodology.