Particle Dampers—Vibration Reduction Through Distributed Dissipation Over Complex Particle Shapes

For the reduction of unwanted vibrations in technical applications solid-particle-filled devices, generally called particle dampers (PDs), have shown great benefits over other devices. However, a systematic design of particle dampers for a specific application proves difficult due to the highly nonlinear behaviour. Therefore, various factors influencing the performance of particle dampers are to be investigated to optimize their behavior. A first improvement approach is adding an additional liquid inside the PD. Its motion is modeled using the smoothed particle hydrodynamics (SPH) method and the discrete element method (DEM) is used to model the motion of solid particles. In order to validate the simulation models, also a laboratory experiment is set up. The insights gained during experiments were utilized to identify and validate the DEM and SPH models. The solid particle shape plays a profound role in enhancing the damping performance. To investigate the effects of complex particle shapes, the simulation model is adapted for non-convex particles. The complex shapes were manufactured using a Stereolithography 3D printer. In order to gain a deeper insight, also a numerical study is presented which investigates the effects of solid-liquid ratio on the dissipated kinetic energy.An additional option are complex 3D rigid obstacle-grids, deliberately introduced inside the PD. In the simulations, the rigid obstacle-grid is described using a triangular surface mesh and to speed up the collision detection process, efficient bounding volume hierarchy data structures were used. The experimental setup is also changed to allow a forced excitation through an electromagnetic shaker. Furthermore, a numerical study indicates that the obstacle-grid cell-size has a profound effect on the dissipation. Finally the broadband characteristics of PDs were systematically analyzed and a performance metric is deduced.