Improving optimal chatter control of slender cutting tool through more accurate tuned mass damper modeling

Abstract

The slender cutting tools are employed in many conditions like boring and milling processes, but those machining processes often accompany with chatter phenomenon which will aggravate the machining efficiency and surface quality. The use of tuned mass damper (TMD) to damp slender tools is considered as a practical and effective way for chatter suppression. Generally, the TMD is embedded inside the hollow cutting tool with two spring-damping elements supporting the mass block at both ends. For the convenience of optimization calculation, the damped tool is generally modeled as an oscillation system with two equivalent lumped mass. With this simplified model, the difference of vibration displacements between two spring-damping elements is ignored. This makes it very difficult to tune the TMD to the best according to the optimization result in practical application especially when both cutting tool and TMD have a slender characteristic. This paper improves the optimal chatter control through a more accurate modeling method which considers the cutting tool as a cantilever Euler–Bernoulli beam and the TMD as a two degrees of freedom system including translation vibration and rotation vibration of the mass block. Based on the proposed model, the influences of the position and length of TMD on the optimal design parameters of two spring-damping elements are analyzed through a series of optimization. The results show that there are great differences in the chatter control mechanism of two spring-damping elements and it is very important to choose respective appropriate stiffness and damping parameters for two spring-damping elements in the TMD damped slender cutting tools. Only in this way can the TMD be tuned in practice to the best performance for chatter control of slender cutting tools. Furthermore, based on the simulation results and comparisons with other conventional modeling methods, the difference and superiority of tuning optimization are discussed and the accuracy and practicability of the proposed modeling method are verified with a designed damped end mill cutter and some impact tests.