Partition five-axis surface machining of CFRP laminate structures considering fiber orientation

Abstract

ABSTRACT Carbon Fiber Reinforced Polymer (CFRP) is commonly employed in advanced industries, acclaimed for their outstanding mechanical properties. The inherent anisotropy of CFRP necessitates careful consideration of the Fiber Cutting Angle (FCA) to achieve optimal surface quality during machining, a challenge that intensifies with curved surface components due to the continuous variability of FCA. In the machining of CFRP curved surfaces, the presence of local singularity precipitates abrupt changes in tool orientation, adversely affecting surface integrity and machining efficiency. To solve this problem, this study proposed a toolpath partitioning method specifically designed for the machining of CFRP curved surfaces, aiming to mitigate the effects of local singularity. Additionally, a novel tool positioning strategy accounting for dual fiber orientations in the machining of bidirectional CFRP curved surfaces was developed. The practical applicability of these methodologies was assessed through the manufacturing of an internal fixation plate via 5-axis machining of bidirectional CFRP laminates. Comparative microscopic observations and surface profile assessments demonstrate a marked improvement in surface quality relative to traditional 3-axis machining, alongside a 25% reduction in machining time compared to 5-axis machining processes absent the partitioning method.