Simulation-Based Development and Experimental Validation of Tool-Integrated Rotary Particle Dampers

• Applicants: Professor Dr.-Ing. Dirk Biermann; Professor Dr.-Ing. Peter Eberhard
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 534586369

Milling, especially of large components made of high-strength steels, is often associated with pronounced, regenerative chatter vibrations. Rotary particle dampers (RPD) integrated into the tool have proven to be a promising approach to vibration reduction in this context. However, the targeted design is complicated by the complex interactions involved. While purely experimental investigations do not allow a view of the particle movements in the operating state, simple simulation approaches do not take into account many influencing parameters from the tool system. Also, a large number of relevant simulation contact parameters have to be determined experimentally. Furthermore, knowledge of the particle movement inside the RPD is necessary for a further RPD improvement. A combined approach is therefore essential for the targeted design of RPD in a milling tool. Mesh-free Lagrangian methods are used to simulate the particle movements in the RPD. In order to achieve simulation results in a shorter time, the particle motions in a representative sub-volume of the PD are simulated and the dissipation mechanisms acting in the entire damper are approximated using periodic boundaries. The experimental data required for the simulation are levied using a specially designed analogy test setup, with which the system vibrations resulting from the real milling process are reproducibly generated without the use of further material. This allows a comprehensive experimental analysis of the damping mechanisms acting in the RPD. In conjunction with comprehensive simulations, this combined approach is intended to provide a deeper understanding of the underlying dissipation process under acting centripetal force. For increased energy dissipation, a high freedom of movement of the particles used in the damper is required. In order to increase the relative movement between the particles, various constructive approaches will be investigated. In particular, the influence of complex PD internal structures as well as additionally introduced fluid on the particle movements in the dampers will be examined. In final application tests with an additively manufactured milling tool with integrated RPD, the damping behaviour of the RPD concept developed in the experiments and simulations will be investigated when milling a higher-strength steel material. Through the interdisciplinary combination of the competences of the Institute of Technical and Computational Mechanics at the University of Stuttgart and the Institute of Machining Technology at the TU Dortmund University, a solution is developed for the still very demanding task of minimizing vibrations during milling. Superordinately, the fundamental investigations also enable a substantial extension of the elementary knowledge on dissipation-efficient RPD design.

• DFG Programme: Research Grants