Vibro-impact model and validation of the axial dynamics of a vibration-assisted drilling tool

A lumped parameter vibro-impact model is proposed to describe the axial dynamics of a vibration-assisted drilling tool prototype, developed to improve the drilling efficiency in hard-rock drilling applications. The purpose of this work is twofold: to develop a new mathematical model that represents the axial dynamics of a vibration-assisted drilling tool, and to validate the proposed mathematical model with field data. The proposed model has seven degrees-of-freedom model with four impact surfaces. High-frequency field data, measured at multiple locations, are used to validate the mathematical model. The results show an overall good match between field data and model outputs, as the vibro-impact model is capable of capturing and reproducing the main dynamic behavior of the vibration-assisted drilling tool. Furthermore, the proposed model is able to reproduce complex dynamic behavior with little computational cost, due to the low number of degrees-of-freedom.