Vibration Assisted Machining (VAM) refers to a non-conventional machining process where
high-frequency micro-scale vibrations are deliberately superimposed on the motion of the
cutting tool during the machining process. The periodic separation of the tool and workpiece
material, as a result of the added vibrations, leads to numerous advantages such as reduced
machining forces, reduction of damages to the material, extended tool life, and enabling the
machining of brittle materials.
Vibration Assisted Drilling (VAD) is the application of VAM in drilling processes. The
added vibrations in the VAD process are usually generated by incorporating piezoelectric
transducers in the structure of the toolholder. In order to increase the benefits of the added
vibrations on the machining quality, the structural dynamics of the VAD toolholder and its
coupling with the dynamics of the piezoelectric transducer must be optimized to maximize
the portion of the electrical energy that is converted to mechanical vibrations at the cutting
edge of the drilling tool.
The overall dynamic performance of the VAD system depends of the dynamics of its
individual components including the drill bit, concentrator, piezoelectric transducer, and
back mass. In this thesis, a substructure coupling analysis platform is developed to study
the structural dynamics of the VAD system when adjustments are made to its individual
components. In addition, the stiffness and damping in the joints between the components of
the VAD toolholder are modelled and their parameters are identified experimentally. The
developed substructure coupling analysis method is used for structural modification of the
VAD system after it is manufactured. The proposed structural modification approach can be
used to fine-tune the dynamics of the VAD system to maximize its dynamic performance
under various operational conditions. The accuracy of the presented substructure coupling
method in modeling the dynamics of the VAD system and the effectiveness of the proposed
structural modification method are verified using numerical and experimental case studies. / Graduate
| Identifer | oai:union.ndltd.org:uvic.ca/oai:dspace.library.uvic.ca:1828/11890 |
| Date | 28 June 2020 |
| Creators | Ostad Ali Akbari, Vahid |
| Contributors | Ahmadi, Keivan |
| Source Sets | University of Victoria |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
| Rights | Available to the World Wide Web |
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