Particle Dampers – Vibration Modification by Distributed Dissipation originating from Complex Particle Shapes and Fluid/Solid Interactions

颗粒阻尼器的应用是一种很有前途的振动修正方法。颗粒阻尼器在很大的频率范围内工作，它们涵盖了额外的功能，如最大限度地减少噪音或作为承重部件，而它们非常坚固，适用于更大的温度范围。颗粒阻尼器的特性是由几种物理现象共同作用而形成的。到目前为止，还没有令人满意的预测模拟方法，考虑到所有这些物理过程的相互作用，并在这样做是有用的适当的调查，了解粒子dampers.The本项目的目的是更深刻的了解粒子dampers.For优化设计。颗粒阻尼器的功能性的重要点之一是颗粒和壳体之间的大量接触。因此，在本项目中，颗粒建模与离散元法（DEM）。由于其无网格特性，可以模拟颗粒堆的大瞬态位移。为了影响耗散，用非凸颗粒代替简单的球体。在第一步中，将开发用于在这些颗粒之间施加摩擦的算法。一个正确的科学研究通常基于两个支柱：模拟和实验。我们希望在每一项工作任务中进行小实验;通过振动器进行刺激的主动实验和用钟摆进行被动实验。除了粒子的复杂形状之外，我们还想开发一种新的方法来预测由于粒子撞击而产生的声音。在这样做时，可以优化更智能的阻尼器，该阻尼器用于降低工作机器的噪声，考虑到噪声水平本身以及同时产生的能量耗散。另一点是由固体颗粒和流体的混合物组成的阻尼器的填充。因此，在耦合流体（光滑粒子流体动力学建模）与粒子的经验将被用来开发一种新的方法，用于耦合非凸粒子与流体。这种方法被用来调查潜在的改善能量耗散时，一定量的流体被添加。损伤在许多技术应用中起着重要作用。最后但并非最不重要的是，我们要实施一个简单的损伤方法到DEM，相邻的颗粒之间，也是住房，并以这种方式调查的影响，损坏的阻尼。

The application of particle dampers is a promising alternative for the modification of vibrations. Particle dampers are working over a large frequency range, they cover additional functions like minimizing noise or being a load bearing part, whereas they are very robust and are applicable over a larger temperature range. Several physical phenomena playing an important role for particle dampers and are interacting to fulfill the features of the damper. Until now there is no satisfying predictive simulation approach which takes the interaction of all those physical processes into account and in doing so is useable for a proper investigation for the understanding of particle dampers.The aim of this project is the more profound understanding of particle dampers for an optimal design. One of the important points for the functionality of a particle damper are the numerous contacts in between the particles and the housing. Therefore, in this project the particles are modeled with the Discrete Element Method (DEM). Due to its mesh-free character it is possible to model the large transient displacements of the particle pile. For influencing the dissipation simple spheres are replaced with non-convex particles. In a first step an algorithm for applying friction between those particles will be developed. A proper scientific investigation is often based on two pillars: simulation and experiment. We want to carry out small experiments in every working task; active experiments with stimulation via a shaker and passive ones with a pendulum. Besides the complex shape of the particles we want to develop a new method to predict the production of sound due to the impact of particles. In doing so, it is possible to optimize a smarter damper which is used for reducing the noise of a working machine, regarding the noise level by itself and simultaneously the resulting energy dissipation. Another point is the filling of the damper consisting of a mixture of solid particles and a fluid. Therefore, the experience in coupling a fluid (modeled by Smoothed Particle Hydrodynamics) with particles will be used to develop a new approach for coupling non-convex particles with a fluid. This approach is used to investigate the potential improvement of energy dissipation when a certain amount of fluid is added. Damage plays an important role in many technical applications. Last but not least we want to implement a simple damage approach into the DEM, between adjacent particles and also the housing and in this way to investigate the influence of damage to the damping.