Journal of Sound and Vibration xxx (xxxx) xxx Please cite this article as: Arjun Patel, Journal of Sound and Vibration, https://doi.org/10.1016/j.jsv.2021.116594 Available online 2 November 2021 0022-460X/© 2021 Elsevier Ltd. All rights reserved. Optimally tuning an absorber for a chatter-resistant rotating slender milling tool holder Arjun Patel , Devang kumar Talaviya , Mohit Law * , Pankaj Wahi Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016, India A R T I C L E INFO Keywords: Chatter Milling Absorber Vibration Tool holder Rotor dynamics ABSTRACT Machining of parts with deep pockets necessitates the use of long slender milling tooling systems with absorbers integrated within them to make the milling process chatter vibration resistant. As milling tools rotate, their dynamics change with speed. Hence, the use of classical analytical methods of tuning absorbers that presume the primary system to have fxed parameters may result in suboptimal designs. To address this, we present methods to tune an absorber integrated within a rotating milling tool holder while accounting for its speed-dependent characteristics. The milling tool holder is modelled as a rotating cantilevered Euler-Bernoulli beam with small distributed viscous damping and a secondary absorber system attached at a point along its length. The governing equations of motion account for all the artifacts associated with rotation viz. gyroscopic, Coriolis, and the centrifugal effects. Rotational effects couple vibrations in orthogonal planes and make the cross frequency response functions as fexible as the direct ones. Since these speed-dependent dynamic characteristics govern the chatter-free machining stability limits, maximization of this limit is treated as the objective function to fnd the optimal mass, stiffness, and damping of the absorber. We fnd that an optimally tuned absorber using the proposed approach results in a~16.5 fold improvement in the chatter-free machining capability as compared to a~11.5 fold improvement using other classical methods of tuning the absorber. 1. Introduction Milling of parts with deep pockets necessitates the use of long slender milling tooling systems. These slender tools tend to vibrate under the action of cutting forces. These process-induced excitations may result in large amplitude unstable regenerative chatter vibrations that may damage the part quality, the tool, and the machine tool system. Often, the only feasible solutions to mitigate such unwanted vibrations of slender tooling systems are to improve their dynamic stiffness and/or their vibration absorption capacity. Solutions for milling tooling systems to improve their vibration characteristics have involved the use of holders made of high strength composites [1–3], the use of constrained layer damping in tool holders [4], the use of damped collets inside milling tool holders [5], and the use of damping cores integrated within the tool holders [6,7]. Other solutions have focused on frictional damping within the tool [8,9], and on integrating tuned mass dampers (absorbers) [10–13] with the tool holders. Of these different methods, the methods of integrating absorbers within tooling systems are preferred due to their simple designs and ease of implementation. Further, it has also been established that the tuned absorber is practically viable in industrial settings [14]. Hence, this paper focuses its attention on integrating an optimally tuned absorber within milling tool holders to make them more chatter-resistant. * Corresponding author. E-mail address: mlaw@iitk.ac.in (M. Law). Contents lists available at ScienceDirect Journal of Sound and Vibration journal homepage: www.elsevier.com/locate/jsvi https://doi.org/10.1016/j.jsv.2021.116594 Received 7 July 2021; Received in revised form 18 October 2021; Accepted 28 October 2021