Vibration System Of Rotary Ultrasonic Machining Finite Element Analysis And Optimization

Ultrasonic machining technology have not been promoted greatly in China, the key reason is in many key technology of ultrasonic machining vibration system there are still technical bottleneck, the design accuracy of vibration system directly affects the ultrasonic machining work efficiency, so it has important research value.This paper using theory of the longitudinal vibration to structural design for the ultrasonic vibration system’ tool and the variable amplitude rod. Through the theoretical calculation to get round straight bar half wavelength longitudinal vibration frequency 20000 Hz the length size is 129 mm, and the finite element modal and resonant analysis verify its natural frequency and the resonant frequency. By theoretical calculation preliminary obtained various size parameters of the variable amplitude rod. And used modal analysis and harmonic response analysis for variable amplitude rod, determine the horn longitudinal vibration mode frequency is 19397 Hz, the resonance frequency is 18176 Hz, the resonant frequency is not in the ultrasonic frequency range of 19000Hz~21000Hz.This paper is also processing simulation for connected to different key parts of the ultrasonic machining vibration system, based on the study of normal contact stiffness fractal model and tangential contact stiffness fractal model of the two key parts junction surface, build a model of junction surface virtual material, virtual material’ thickness and material properties can solve by normal contact stiffness fractal model theory and tangential contact stiffness fractal model theory. The ultrasonic vibration system is the key parts for connecting surface using virtual material after processing of modal analysis and harmonic response analysis, the need to get the longitudinal vibration resonant frequency is 18979 Hz, not in the ultrasonic frequency range of 19000Hz~21000Hz, and therefore need to key parts of vibration system in size optimization.The last part of the thesis is the size optimization design of vibration system. The parametric modeling of the vibration of the system, and then establish the mathematical optimization model, using the finite element software to optimize. After optimization, the optimal model can make the resonant frequency of vibration system, namely, the vibration frequency of the vibration system at the same time in the ultrasonic frequency range of 19000Hz~21000Hz to ensure the most close to the resonant frequency of 20000 Hz. Which not only makes the ultrasonic vibration system can work normally, but also improve the machining efficiency and precision of the ultrasonic vibration system.