Design Of Two-Dimensional Ultrasonic Vibration Cutting Device With Double-Excitationbased On FEM

As an advanced manufacturing technology,two-dimensional ultrasonic vibration cutting has a better cutting effect than ordinary cutting.Especially in the difficult-to-cut materials,for example,optical glass,monocrystal silicon,ceramic and stainless steel,the cutting advantage is more obvious.But there are still some deficiencies that need to be solved and improved,such as large errors in the motion coupling of the vibration system.In order to solve this problem and continue to enhance its performance advantages,this doctoral dissertation will concentrate on the study of two-dimensional ultrasonic elliptical vibration cutting device.The main contents and results are as follows.(1)A design of the ultrasonic-vibration-assisted-cutting device is described,which has a pair of orthogonal longitudinal vibration inputs producing an elliptical trajectory through the two pieces of flexible metal connecting longitudinal compound transducers to a cutting tool.A fixture system is designed according to the node locations of the longitudinal compound transducers.(2)The sizes of the transducers and the ultrasonic horn are determined by the analytical method.With respect to this design,the finite element analysis method is used to calculate vibration modes and harmonic response of the ultrasonic elliptical vibration system with the orthogonal double longitudinal vibration inputs.The model of the system is obtained that meets the requirements of vibration modes,node locations and frequencies.The results of the harmonic response analysis show that: 1)the system can synthesize the ultrasonic elliptical trajectory;2)the phase differences between the cutting tool's outputs and the inputs from the transducers are very close;3)the shape of the ultrasonic elliptical trajectory can be changed by adjusting the phase difference of the two excitation signals.(3)The performance measurement of the ultrasonic oscillator is carried out by the impedance analyzer and the laser vibrator.The two-dimensional ultrasonic elliptic vibration system which meets the design requirements.The average frequency(48900Hz)of the true resonance frequency of the two groups of vertical composite transducers is taken as the excitation frequency of the input of the vibration system.(4)The ultrasonic elliptical vibration cutting tests and non ultrasonic tests are made for the two materials of brass and ordinary.The results show that the effect of two-dimensional ultrasonic elliptical vibration cutting is better than that of ordinary cutting.