Celikag, H., Ozturk, E. orcid.org/0000-0001-9982-2837 and Sims, N.D. (2021) Can mode coupling chatter happen in milling? International Journal of Machine Tools and Manufacture, 165. 103738. ISSN 0890-6955
Abstract
In milling, two different self-excited vibrations have been reported; regenerative and mode coupling chatter. The regenerative chatter mechanism has been extensively studied and validated with tests whereas mode coupling chatter mechanism was reported a long time ago for threading operations. The presented mode coupling chatter models were based only on current vibrations of the system but not on the delayed vibrations. With the increase in the research carried out on robotic milling operations, the low frequency severe self-excited vibrations at high spindle speeds were claimed to be mode coupling chatter by many researchers. However, the justification of mode coupling chatter mechanism is absent from predicted stability boundaries and a strong evidence distinguishing it from regenerative chatter mechanism is not present. Additionally, mode coupling chatter models applied to milling was based on threading operations and hence they were not capturing the characteristics of intermittent milling process. Therefore, this paper focuses on the diagnosis of mode coupling chatter in robotic milling. Mode coupling chatter principles are applied to milling process considering its intermittent characteristics. The zeroth order approximation for mode coupling chatter mechanism is adapted for milling and extended to multi frequency approximation. Mode coupling chatter stability boundaries are calculated, explored with tests and compared with regenerative chatter stability boundaries. Results show that mode coupling chatter stability boundaries are very low and vaguely dependent on the spindle speed. This contradicts the stability observed in the experimental tests. Hence, it is concluded that mode coupling chatter in milling is not possible, because the assumption of the chip thickness depending only on current vibrations does not apply to milling operations. The novelty of the presented paper is the theoretical and experimental justification that mode coupling chatter is not possible in milling operations.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). |
Keywords: | Mode coupling chatter; Regenerative chatter; Robotic milling |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Advanced Manufacturing Institute (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 11 May 2021 16:30 |
Last Modified: | 25 Feb 2022 14:08 |
Status: | Published |
Publisher: | Elsevier BV |
Refereed: | Yes |
Identification Number: | 10.1016/j.ijmachtools.2021.103738 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:174013 |