Analysis and implementation of chatter frequency dependent constrained layer damping tool holder for stability improvement in turning process

Abstract

The machining stability is closely affected by dynamics behavior of the tool holder in turning operation. In this paper, the constrained layer damping (CLD) tool holder with chatter frequency dependent dynamics is analyzed to further improve machining stability. The dynamics behavior of CLD tool holder is first considered to be influenced by the chatter frequency due to the viscoelastic material. The mechanical properties of viscoelastic materials are determined by the testing frequency. Analytical models are built to calculate the modal parameters such as damping ratio. The chatter frequency dependence further increases the critical depth of cuts in stability lobes. Then, dimensions of the CLD structure are simulated and selected to increase damping where the chatter frequency is assumed to approximate the natural frequency, after that the developed CLD tool holder is manufactured. Lastly, modal tests and cutting experiments are performed for verification. The damping ratio of developed CLD tool holder are increased by 99% compared to that of conventional steel tool holder. It has been proved that the developed CLD tool holder can further improve machining stability with better damping performance especially when the chatter frequency is farther from the natural frequency.