Abstract:

On account of heterogeneous and anisotropic nature of the carbon fiber reinforced plastic (CFRP) in macroscopy and a special state of fiber-resin mixture in microscopy, delamination, cracks, etc. are easily generated in the manufacturing process, which greatly reduces the bearing capacity and machining accuracy of final parts. The key to improve machining quality lies in exploring the mechanism of CFRP subsurface damages for the purpose of damage reduction. In this paper, the orthogonal cutting simulation model that can realize the unidirectional CFRP continuously dynamic cutting process at any fiber orientation is developed based on macroscopic anisotropy constitutive behaviors, Hashin initial failure criterion and the damage evolution. Also analysis of subsurface damages in the unidirectional CFRP continuously dynamic cutting process of is made to acquire influences of fiber orientation, cutting parameters and tool geometries on the damage depth. Detailed results are listed as follows: Subsurface damages are mainly impacted by fiber orientation, and with the increase of the orientation, the cutting force rises, and so is the damage depth. The mechanism of subsurface damages is matrix fractures led by excessive cutting force and the resulting damage propagation; the damage depth first increases and then decreases with the augment of the tool rake angle for unidirectional CFRP with 135° fiber orientation.

Key words: continuously cutting process, finite element analysis, subsurface damage, carbon fiber reinforced plastic(CFRP)