Simulation-based design of passive vibration damping using distributed particle dampers with application to active flexible multibody systems

颗粒阻尼器是一种设计简单的被动阻尼元件。粒状颗粒嵌入在附接到振动结构的容器中或嵌入在振动结构中的孔内。由于结构振动，动量被传递到颗粒材料，并且能量由于颗粒间的碰撞和摩擦效应而被耗散。在过去的几十年里，人们对颗粒阻尼器的兴趣越来越大。粒子阻尼很容易应用，即使在现有的硬件，它已被证明，它可以至少是有效的其他阻尼技术。这种耗散能量的有效性不限于单一频率，而是存在于更宽的频率范围内，这在传统的阻尼解决方案中是不常见的。此外，颗粒阻尼器对各种形状和尺寸以及各种颗粒类型和材料都有很强的适应性。尽管颗粒阻尼器的效率已经在实验中得到了证明，但到目前为止，它们只在少数不同的工程应用中使用，大多数是针对非常特定的系统设计的。这可能是由于粒子阻尼器中的过程非常复杂并且尚未完全理解。另外，目前的设计过程主要是基于实验的试错策略。本研究的目标是开发一种新的基于仿真的设计方法，用于使用分布式颗粒阻尼器的轻质结构和机器的被动振动阻尼。通过这种新的基于仿真的设计方法，这是在部分独立的具体应用，它将有可能扩展到各种不同的应用程序的颗粒阻尼器。这对于目前通常缺乏有效的被动振动阻尼方法的轻质系统尤其有意义。首先，独立于应用，其目的是开发具有预定义特性的小颗粒阻尼器单元。这些单独的颗粒阻尼器应形成一个组件，最终用于特定应用的整体阻尼概念。因此，可能具有不同特性的这些颗粒阻尼器中的几个应该最佳地分布在柔性体上，以便在宽范围的频率和振幅上实现最大的阻尼效率。对于数值研究，离散元方法模型和宏模型，可以更容易地集成在柔性多体系统，开发。这些模型是阻尼器开发的基础。数值计算工作与实验研究密切相关。作为动机的例子，所开发的方法的应用程序上的主动柔性多体系统的选择。

Particle dampers are simply designed passive damping elements. Granular particles are embedded in a container attached to a vibrating structure or within holes embedded in the vibrating structure. Due to the structural vibrations momentum is transferred to the granular material and energy is dissipated due to inter-particle impacts and frictional effects. In the last decades there has been an increased interest in particle dampers. Particle damping is easy to apply even in already existing hardware and it has been shown that it can be at least as effective as other damping techniques. This effectiveness in dissipating energy is not restricted to a single frequency but exists over a broader frequency range which is not usual in conventional damping solutions. Moreover, particle dampers are highly adaptive with various forms and sizes and a variety of particle types and materials.Despite the efficiency of particle dampers which was demonstrated experimentally, so far they have been used only in few different engineering applications, mostly designed for a very specific system. This might be due to the fact, that the processes in the particle dampers are very complex and not fully understood yet. Also the design process is currently mostly based on experimental trial-and-error strategies.The research objective is the development of a new simulation-based design methodology for passive vibration damping of lightweight structures and machines using distributed particle dampers. By such a new simulation-based design methodology, which is in parts independent of the specific application, it will be possible to extend particle dampers to a variety of very different applications. This is especially of interest for lightweight systems where currently often efficient passive vibration damping methods are lacking. Firstly, independent of the application, it is aimed to develop small particle damper units with predefined characteristics. These individual particle dampers should form an assembly set, which is ultimately used in the overall damping concept for specific applications. Thereby, several of these particle dampers, possibly with different characteristics, should be distributed optimally over a flexible body in order to achieve a maximal damping efficiency over a wide range of frequencies and amplitudes. For numerical studies Discrete-Element-Method models and macro-models, which can be more easily integrated in flexible multibody systems, are developed. These models are the basis for the damper development. The numerical work is closely accompanied by experimental investigations. As motivation example the application of the developed methods on an active flexible multibody system is chosen.