Full and half-wavelength ultrasonic percussive drills

Li, X. , Lucas, M. and Harkness, P. (2018) Full and half-wavelength ultrasonic percussive drills. IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 65(11), pp. 2150-2159. (doi: 10.1109/TUFFC.2018.2867535)

167947.pdf - Accepted Version



Ultrasonic-percussive drills are a leading technology for small rock drilling applications where power and weight-on-bit are at a premium. The concept uses ultrasonic vibrations to excite an oscillatory motion in a free-mass, which then delivers impulsive blows to a drilling-bit. This is a relatively complex dynamic problem involving the transducer, the free-mass, the drilling-bit and, to a certain extent, the rock surface itself. This paper examines the performance of a full-wavelength transducer compared to a half-wavelength system, which may be more attractive due to mass and dimensional drivers. To compare the two approaches, three-dimensional finite element models of the ultrasonic-percussive stacks using full and half wavelength ultrasonic transducers are created to assess delivered impulse at similar power settings. In addition, impact-induced stress levels are evaluated to optimize the design of drill tools at a range of internal spring rates before, finally, experimental drilling is conducted. The results suggest that full-wavelength systems will yield much more effective impulse but, interestingly, their actual drilling performance was only marginally better than half-wavelength equivalents.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Lucas, Professor Margaret and Harkness, Professor Patrick and Li, Dr Xuan
Authors: Li, X., Lucas, M., and Harkness, P.
College/School:College of Science and Engineering > School of Engineering > Systems Power and Energy
Journal Name:IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
ISSN (Online):1525-8955
Published Online:28 August 2018
Copyright Holders:Copyright © 2018 IEEE
First Published:First published in IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 65(11): 2150-2159
Publisher Policy:Reproduced in accordance with the copyright policy of the publisher

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