超声波取样钻机电耦合特性研究

Research on Electromechanical Coupling Properties of the Ultrasonic/Sonic Driller/Corer (USDC)

摘要:

压电驱动的超声波取样钻具有质量轻、能耗低、无回转部件的特点，可以满足地外岩石采样的需求。电能通过压电陶瓷转换为致动器高频振动的机械能，使其在特定频率做超声的共振。这种超声取样钻的机电耦合特征，使超声致动器的设计变得复杂。基于ANSYS环境，研究超声致动器在机电耦合场边界条件下的动力学特性，其耦合场的模态频率、激励响应与单一机械结构场条件得到的结果具有较好的一致性。结果表明，超声致动器把电能转换机械能过程的机电耦合场相互作用是很弱的。因此，采用解耦方法，超声致动器的设计过程将大大简化。

关键词:超声波取样钻;月球取样;致动器;机电耦合;模态分析;解耦

Abstract:

The Ultrasonic/Sonic Driller/Corer (USDC), driven by the piezoelectric system, can take rock samples in other planets because of the light weight, low energy consumption and no rotating parts. The function of piezoelectric stacks is to convert the electric power into the dynamic power of the high-frequency mechanical vibrations, so the ultrasonic horn vibrates in ultrasonic frequency. It is complicated to design the ultrasonic horn due to electromechanical coupling. Based on the ANSYS environment, the dynamic characteristics of the ultrasonic horn under the boundary conditions of electromechanical was analyzed. The modal frequency and the excitation response of the coupling field were in good agreement with the results obtained from the single mechanical structure field. The result shows that the electromechanical coupling of USDC is very weak in the process of electrical energy converting into mechanical vibrating power and can be neglected for calculation. Therefore, the decoupling method will be adopted to design the ultrasonic horn in order to simplify the design process.

Key words:USDC; lunar sampling; ultrasonic horn; electromechanical coupling; modal analysis; decoupling