Abstract

In this study, the damping torque exerted on a horizontally rotating blade in granular materials under gravity was investigated. To capture the stirring behaviour of the granular materials in detail, a mechanical stirring apparatus was fabricated. The rotating blade was driven sinusoidally by a shaker through a ball screw mechanism. It was found that energy dissipation depends on various parameters such as particle material and particle size. Energy dissipation was also calculated using the EDEM® software based on the discrete element method. To verify the validity of the numerical simulation model, numerical simulation results were compared with experimental results.

Abstract

Tuned mass dampers, consisting of a mass, spring, and damper, are widely used for vibration suppression in structures. Despite being small and lightweight, these dampers exhibit excellent damping effectiveness. However, there are issues such as performance degradation due to the aging of the spring and damper, as well as the need for frequent maintenance. Therefore, as an alternative vibration control device that does not rely on these components, a rolling-ball damper is proposed. This damper consists of a container with a lid and multiple enclosed particles on its curved surface. By utilizing the contact between particles and the friction between particles and the container, the rolling-ball damper can absorb and suppress the vibration energy imposed on the structure to which the container is attached. In this study, we investigated the characteristics of the rolling-ball damper in a horizontal vibration system. We experimentally verified the effects of the size and number of enclosed particles on damping performance. Furthermore, numerical simulations were conducted by the discrete element method using EDEM® software and the multibody dynamics simulation method using MotionSolve® software. A comparison between experimental and numerical simulation results demonstrated the effectiveness of numerical calculations in predicting the amplitude response