title: Modeling and computer simulation of ultrasonic/sonic driller/corer (USDC).
abstract: Simulation and analytical models for the ultrasonic/sonic drill/corer (USDC) are described in this paper. The USDC was developed as a tool for in-situ rock sampling and analysis in support of the NASA planetary exploration program. The USDC uses a novel drive mechanism, which transfers ultrasonic vibrations of a piezoelectric actuator into larger oscillations of a free-flying mass (free-mass). The free-mass impact on the drill bit creates a stress pulse at the drill tip/rock interface causing fracture in the rock. The main parts of the device (transducer, free-mass, bit, and rock) and the interactions between them were analyzed and numerically modeled to explore the drive mechanism. Each of these interactions is normally described by a time-dependent 2- or 3-D model involving slowly converging solutions, which makes the conventional approach unsuitable for USDC optimization studies. A simplified integrated model using tabulated data was developed to simulate the operation of the USDC on desktop PC and successfully predicted the characteristics of the device under a variety of conditions. The simulated results of the model and the experimental data used to verify the model are presented.
authors.affiliation: Jet Propulsion Lab, Pasadena, CA 91109, USA. xbao@jpl.nasa.gov
authors.forename: Xiaoqi
authors.initials: X
authors.lastname: Bao
authors.forename: Yoseph
authors.initials: Y
authors.lastname: Bar-Cohen
authors.forename: Zensheu
authors.initials: Z
authors.lastname: Chang
authors.forename: Benjamin P
authors.initials: BP
authors.lastname: Dolgin
authors.forename: Stewart
authors.initials: S
authors.lastname: Sherrit
authors.forename: Dharmendra S
authors.initials: DS
authors.lastname: Pal
authors.forename: Shu
authors.initials: S
authors.lastname: Du
authors.forename: Thomas
authors.initials: T
authors.lastname: Peterson