Machining quality and cutting force signal analysis in UD-CFRP milling under different fiber orientation

Increasing usage of carbon fiber-reinforced polymer (CFRP) components in the airplane industry has led to higher demand in the machining quality of CFRP. In order to meet the quality requirements of final assembly, the signal monitoring of various processing parameters can be used to ensure the machining setup in perfect order. In the present work, a set of experiments for UD-CFRP side milling has been carried out with different fiber cutting angle. The effects of fiber cutting angle on machining surface quality as well as the corresponding milling force signal features have been investigated based on time, frequency domain analysis, and wavelet analysis methods. The analysis results demonstrate that, for the against fiber cutting condition, the cutting force signal has a significant increase for high-frequency component energy percentage, and the higher frequency components are more sensitive. In addition, the fluctuation trend of power percentage for frequency band S3 (1500-2500 Hz) and surface roughness is quite close, which can be employed as a monitoring index for CFRP machining surface roughness.