Due to low density, very thin cell walls and hexagonal cell structure, nomex honeycomb composites are considered as difficult to machine materials. CNC machining is the most common method used for the cutting of nomex honeycomb composites but required machining qualities of the nomex honeycomb composites components are not satisfactory due to various machining defects. Therefore, a new nontraditional machining technology rotary ultrasonic machining has been introduced to overcome the machining problems of nomex honeycomb composites because of intermittent contact of cutting tool with workpiece, low cutting force and better machining quality. In this research, a novel Ultrasonic Circular Saw Blade (UCSB) cutting tool and Ultrasonic Circular Knife (UCK) Cutting Tool are introduced and designed for ultrasonic machining of nomex honeycomb composites. Impact of different structural parameters of UCK and UCSB cutting tools on resonant frequency is investigated by FE simulations modal analysis technique on ANSYS workbench. Designs of cutting tools are verified by comparing FE simulations with experimental results and it showed that the resonant frequency and amplitude of cutting tools are good enough to perform rotary ultrasonic machining of nomex honeycomb composites.

With great heat resistance, corrosion resistance, high specific strength and excellent mechanical properties, nomex honeycomb composites are widely used in aerospace industry. However, due to the special properties of the nomex honeycomb composites, traditional high-speed milling is difficult to complete the processing of the material. The ultrasonic processing method is one of the best ways to solve the above problem. In order to improve the ultrasonic power, the size of the ultrasound system structure is normally very large, which is inconvenient and uneconomical for processing the nomex honeycomb composites. A mini ultrasonic cutting system for paper - based honeycomb material is designed in this paper. Its output amplitude is realized under the condition of small size, and its processing performance is verified by experiments. Based on the theoretical analysis, the design parameters of the presented mini ultrasonic cutting system were calculated. The resonant frequency, magnification and amplitude of the system were analyzing by simulation and amplitude test. The results showed the system parameters are consistent with the design value. The processing experiments of the honeycomb material indicated the system can effectively reduce the cutting force and improve the surface quality.