Dynamic Simulation Of The Ultrasonic/Sonic Driller/Corer(USDC)

With the development of aerospace undertaking in our country and the enhancement of the comprehensive national strength, the deep space probe has been in the works. "Sampling" is an indispensable link in lunar exploration and deep space missions of other planets in the future.However, with the low gravity, large temperature difference between day and night, high radiation, and so on, the environmental condition on the surface of moon is much complicated than the earth. In addition, so far people are mainly using the polar energy to conduct the special job outside. Thus, the ordinary drilling method cannot be used on the moon surface. ultrasonic/sonic driller/corer(USDC) have some unique advantages,(such as Simple structure, small volume, light weight, Low energy consumption, no rotary motion, without having to keep rotating torque, no lubrication, and stable performance) which make up for the limitation of the regular drilling cannot implement in the extraterrestrial environment.In order to solve the problems related to the optimization of the ultrasonic/sonic driller/corer(USDC). We need to do some related experiments for the ultrasonic/sonic driller/corer and analysis the influences of the length of drill stem, free mass, horn and drill stem connection to the drilling. For drilling dynamics analysis to understand the energy coupling among the parts of the ultrasonic/sonic driller/corer(USDC).With the help of the general finite element computer program ANSYS, modal analysis between 0~30000Hz of USDC is conducted. Modal analysis obtain the resonant frequency of piezoelectric actuator have little difference in the condition of ignoring piezoelectric effect and short circuit(constant pressure). Modal analysis of piezoelectric actuator can meet the requirements in the condition of without considering piezoelectric effect.After analyses the harmonic response on the piezoelectric actuator coupling field, extract the node displacement at contact position between the horn and drill stem, as impact loads of ultrasonic/sonic driller/corer for LS-DYNA finite element model. The modal analysis determined the length of the drill stem under the free boundary conditions at both ends. Finally, 88 mm and 125 mm drill stem will be simulated in LS-DYNA respectively. The simulation results show that 88 mm drill stem percussion drilling rock produce compressive stress on the surface of rock is bigger than the 125 mm drill stem. From the drill stem shaft shoulder speed, 125 mm drill stem is better than 88 mm drill stem.The drilling the clay brick trials results show that the 2-gram free-mass predicts a higher drilling rate for 88 mm drill stem. The experiments also show that the plug type ultrasonic/sonic driller/corer with free mass shock and vibration better than simply high-frequency vibration drilling. Take the force load in place of vibration excitation force to realize threaded connection ultrasonic/sonic driller/corer which makes simulation in LS-DYNA.Through the work, the plug type connection and threaded connection ultrasonic/sonic driller/corer in the case of free mass which make simulation in LS-DYNA and relevant experiments. All the work in the paper lay a solid foundation on the research and design of USDC.