Ultrasonic longitudinal-torsional vibration-assisted cutting of Nomex (R) honeycomb-core composites

摘要

Nomex (R) honeycomb core sandwich structures have been widely used in the aviation industry because of their special structure and performance. Ultrasonic composite processing was introduced to solve the poor machinability of honeycomb core products when subjected to conventional processing methods. Based on the characteristics of ultrasonic longitudinal-torsional vibration, the motion equation of the machining tool was established. The tool was simplified as a straight blade and slide effect was applied to study the torsional characteristics of the tool. Tests were conducted to investigate the influence of machining parameters on cutting force and surface quality. The results showed that the cutting force required during ultrasonic longitudinal-torsional vibration-assisted cutting was smaller than for ultrasonic longitudinal vibration-assisted cutting, regardless of the spindle speed and the feed rate. Compared to the feed rate, spindle speed has a significant influence on the cutting force. The slide effect is effective when cutting off the fiber and can reduce the formation of burrs. Compared to ultrasonic longitudinal vibration-assisted cutting, shorter burrs, a lower burr rate, and fewer tear defects were observed after ultrasonic longitudinal-torsional vibration-assisted cutting. The surface quality of the honeycomb core composites was improved by increasing the spindle speed during ultrasonic longitudinal-torsional vibration-assisted cutting.