Improving stability predictions in milling by incorporation of toolholder sound emissions

Abstract

In this paper, a new approach for the identification of tool-holder contact parameters is proposed. The identification strategy is based on the sound emitted from the tool-holder combination when impacted in free-free conditions. Additionally, a new contact model, which takes the non-uniform pressure distribution between tool and holder along the tool axes into account, is introduced. Contrary to previous approaches, the proposed method does not require any expensive measurement equipment but only a microphone and a hard object for the impact. The sound spectrum is recorded and model parameters are tuned in a nonlinear optimization until an agreement between the measured sound spectrum and the modeled receptance is observed. The proposed approach is validated in several application cases. Significant improvements in the predicted tooltip dynamics as well as in predicted stability charts are achieved when comparing the results obtained with the new approach against results obtained with a contact model and contact values proposed in literature.