Analytical Model of a Special Percussive Mechanism for Planetary Exploration and Feature Analysis

摘要

The Ultrasonic/Sonic Driller/Corer (USDC), a novel percussive drilling mechanism, is a tool for rock sampling in support of planetary exploration. This mechanism consists of three components: an ultrasonic actuator, a free mass, and a drill bit. The free mass, bouncing between the horn tip and drill bit end, delivers energy from the transducer to the surface of rock. This paper presents an analysis of the collision between the free mass and horn tip/drill bit end. The collision between different components is numerically analyzed by an elastic-dynamic approach, and finite element analysis is used to verify the calculated results. A simplified integrated model is programmed to simulate the operation of this device. Distinct features of this device, i.e.,the failure and optimum states, are obtained from the integrated model and experiments. It is observed that single and multiple collisions may occur between the free mass and horn tip in one collision cycle. A decrease in the vibration amplitude makes multiple collisions and acceleration of the free mass impossible. Moreover, the failure and optimum states are affected by the weight of free mass and preload.(c) 2017 American Society of Civil Engineers.