Research on Ultrasonic Cutting Mechanism of Nomex Honeycomb Composites Based on Fracture Mechanics

doi:10.3901/JME.2015.23.205

Abstract

Abstract: There are many problems, such as work-piece fixed difficultly and dusty chip, which exist in high speed milling Nomex honeycomb composites. They could be solved by using the technology of ultrasonic cutting. Mechanism of cutting Nomex honeycomb composites combining with ultrasonic are studied based on fracture mechanics, so that the rationale are supplied for optimizing those technological parameters and the design of ultrasonic cutting spindle. The ultrasonic cutting process with straight blade cutter is introduced and the dynamical function of cutter is presented. The interaction time relationship between cutter and material is analyzed in the condition of ultrasonic intermittent cutting. According to fracture mechanics, the model of fracture toughness is built with dynamic stress intensity factor to study the micro fracture process of Honeycomb composites. The factors affecting cutting force are analyzed according to the relation of feeding distance and crack propagation length, and it is demonstrated by means of simulation example. The experiment is carried out by means of ultrasonic cutting experimental platform self-made, to compare the cutting force with ultrasonic or not. The result reveals the cutting force with ultrasonic was much less. And it also demonstrates that crack propagation is the main to reduce the cutting force of machining honeycomb composites with ultrasonic. Theoretical analysis and experimental results prove that the research on the ultrasonic cutting mechanism for Nomex honeycomb composites based on fracture mechanics is reasonable and effective.

Key words: cutting force, dynamic stress intensity factor, fracture mechanics, Nomex honeycomb composites, ultrasonic cutting

HUANG Xiuxiu, HU Xiaoping, YU Baohua, WU Shengyou. Research on Ultrasonic Cutting Mechanism of Nomex Honeycomb Composites Based on Fracture Mechanics[J]. Journal of Mechanical Engineering, 2015, 51(23): 205-212.

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