Analytical and numerical investigation on the mechanical behavior of subsurface damage during orthogonal cutting of carbon fiber reinforced polymer composites

Abstract

Rejection of parts at the assembly stage due to poor machining quality is major problems in the manufacturing of structural components from carbon fiber reinforced polymer composites. On-line monitor of the multi-scale failure modes during machining to reveal the damage formation mechanisms is a great challenge for industries. Therefore, there is a great need for multi-scale mechanical modeling method. This study will address this problem through a combined analytical–numerical method. A microscale analytical model considering the cutting edge of tool is established to clarify the effect of cutting edge radius on the fiber deformation and failure mechanism. In addition to the analytical model, a user-defined subroutine based on maximum stiffness degradation model of composite is implemented into the two-dimensional macroscopic anisotropic finite element code to characterize the dynamic processes of subsurface damage initiation and propagation. It is found that the extent of uncut fibers increases as the cutting edge radius increases when the fiber orientation is less than 90°. The subsurface damage is relatively serious when the fiber orientation is greater than 90°, and the cutting edge radius has no obvious effect, while the tool rake angle has a significant impact. The results provide theoretical basis for the development of new tools and new technologies to the composite machining.