Study Of An Ultrasonic Acoustic System Of The Pointed Cutter

Nomex honeycomb materials, as a kind of typical composite material, have been widely usedin aerospace, construction, automotive and many other fields, because they have multipleadvantages such as small density, high specific stiffness and strength, stable performance, goodinsulation and so on. However as a result of its special honeycomb structure and material matrix,the poor machinability of Nomex honeycomb materials can cause bad machining quality in theprocessing. It has a significant effect that ultrasonic cutting technique has been used in Nomexhoneycomb materials processing. Ultrasonic cutting tool has small cutting force, good cuttingquality, non-sticking knife, high processing efficiency and other excellent features. Ultrasoniccutting tool is one of the factors for the superiority of ultrasonic cutting technique. Therefore, it isvery practical significance to design an ultrasonic cutting device with an acoustic system.According to Nomex honeycomb materials roughing, this paper studied an ultrasonicacoustic system of the pointed cutter and an ultrasonic cutting spindle. The main content isdivided into six parts as follows.In the first chapter, the characteristics and processing method of Nomex honeycomb materialwere described, and its research and development status at home and abroad was summarized.This paper also introduced the research status of ultrasonic cutting technique, ultrasonic cuttingtool and ultrasonic cutting spindle at home and abroad. The meaning of research and content ofthis paper was expounded.In the second chapter，dynamic response of Nomex honeycomb materials was studied. Anultrasonic cutting spindle was designed on the basis of the existing ones, which included thedesigning of spindle structure, bearings and motor. A brief study on ultrasonic cutting techniqueof honeycomb materials was done from the two aspects.In the third chapter, an ultrasonic acoustic system of the pointed cutter with harmonicfrequency20kHz was designed according to the design method of ultrasonic acoustic system. Itincluded the theoretical analysis, parameter designing and3D modeling of the piezoelectrictransducer and amplitude transformer, and the structure designing and dynamic model analysis ofthe ultrasonic pointed cutter.In the fourth chapter, the finite element analysis method was discussed from two aspects ofmodal analysis and harmonic response analysis. ANSYS Workbench was used to do finiteelement analysis of ultrasonic acoustic system. Firstly, the effect of tool geometry on the naturalfrequency was studied to find the optimal geometry of the tool which has the optimal modal shapes and natural frequencies. Secondly, modal analysis and harmonic response analysis ofamplitude transformer and pointed cutter combination was done to studied to the dynamiccharacteristics of the combination under the harmonic frequencies.In the fifth chapter, amplitude measurement experiment of the self-developed pointed cutterunder the harmonic frequencies was done by Laser displacement sensor CD5system to verify therationality and practicability of the tool design.In the last chapter, the main research content of this paper was summarized. And furtherresearch on ultrasonic cutting technique of Nomex honeycomb materials and ultrasonic acousticsystem of the pointed cutter was discussed and prospected.