Bi-stability induced by motion limiting constraints on boring bar tuned mass dampers

Zsolt Iklodi,David A.W Barton,Zoltan Dombovari

doi:10.1016/j.jsv.2021.116538

Zsolt Iklodi, David A.W Barton + Show 1 more

Open Access

https://doi.org/10.1016/j.jsv.2021.116538

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Abstract

This paper investigates the effect of displacement constraints on the attenuation performance of tuned mass dampers (TMDs) used in boring and turning applications. A simplified piecewise-smooth mechanical model is investigated through time domain simulations and hybrid periodic orbit continuation, first under harmonic excitation, then under regenerative cutting load. A quasi-frequency response function is derived for impacting TMDs through composition of different families of period-1 orbits, then an acceptability map for turning is formulated based on the appearance of cutting-edge contact-loss and fly-over events. The bi-stable domain boundaries are determined through two parameter continuation of contact-loss grazing events. It is shown that in both cases arising rigid body collisions can significantly hinder TMD damping performance and lead to resonance problems or machine tool chatter.

Highlights

Tuned mass dampers have been successfully implemented in industrial machining solutions [1, 2], such as the boring bars discussed in [3]
Time domain simulations were employed in the initialization phase of all continuation tasks, as the previously formulated boundary value problems (BVPs) is highly sensitive of the initial state, especially when it comes to event times and event order
The general order of investigation was to initialize an orbit by time domain simulation, correct and follow it to grazing events via continuation, simulate new initial orbits and repeat the process until the target parameter domain is covered

Summary

Introduction

Tuned mass dampers have been successfully implemented in industrial machining solutions [1, 2], such as the boring bars discussed in [3]. In principle installing a mass and spring system with optimal tuning can completely cancel out resonant vibrations by October 7, 2021 utilizing the antiresonance phenomenon. In practice this simple solution is only applicable when the natural frequency of the system and the operational bandwidth of excitation is constant and known. In machining applications both of these parameters often vary due to changing spindle speeds or tooling and fixture configurations

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