Damage behaviors of unidirectional CFRP in orthogonal cutting: A comparison between single- and multiple-pass strategies

Carbon Fibre Reinforced Plastics/Polymer (CFRP) composites has experienced a rapid revolution, requiring the accurately controllable machining technology. Although efforts have been paid on CFRP machining, most of them focused on the single-pass orthogonal cutting where the perfect unprocessed surfaces were employed as the initial state. The reality is however the multiple-pass cutting with the progressive cut depths has been widely used in the industries, where the influence of the defects generated in the previous passes on the following cuts can not be ignored. To fill this gap, this paper investigated the damage behaviors of unidirectional CFRP in orthogonal cutting with the special emphasis on the difference between the single- and the multiple-pass strategies. The good agreement were found between the experimental and simulation results, where the maximal relative errors were separately 10.1%, 9.2%, and 8% for fibre pull-out depth, fibre-matrix debonding depth and cutting forces. Further discussion based on the model can draw the conclusion that, the employment of the multiple-pass cutting strategy can improve the fibre breakage length by 40%, the fibre pull-out depth by 63%, and the fibre-matrix interface debonding by 25%. This work is anticipated to not only open a new avenue to provoke more in-depth thoughts of CFPR behaviors in cutting but also to provide the practical guidance for industrial CFRP high-quality machining.