Damping Chatter Vibrations of a Boring Bar by an Integrated Impact Damper

Slender boring bars are susceptible to cutting process-induced vibrations that can result in large amplitude chatter vibrations. Chatter can damage the workpiece and the tool if not suppressed. This paper proposes a solution to damp boring bar vibrations by integrating an impact damper within the boring bar. The system consists of a mass that collides with the bar to be damped and absorbs its vibrational energy through momentum exchanges. We present an analytical model to characterize the influence of the role of the gap between the impacting mass and the main system and to investigate the role of impacting interface characteristics. Such model-based analysis is the main aim and new technical contribution of this paper. The bar is modeled as an Euler–Bernoulli beam with a ball-like mass assumed placed inside a hollow cavity of the boring bar. Impacting interfaces are modeled using a stiffness and viscous damper system. Governing equations are obtained by applying the extended Hamilton’s principle. Our analysis suggests that the bar’s response reduces when the interface damping is larger than that of the boring bar’s whereas when the interface stiffness is larger than that of the boring bar’s modal stiffness, there is a slight increase in response. For large interface damping, the gap is found to play a significant role, and no role when the interface damping is low. Since our model is generalized, it can be used to perform such an optimization that can in turn guide prototyping for experimental validation.