Effect of process parameters of shear cutting for carbon fiber–reinforced thermoplastic laminate

The shear cutting in the thickness direction is suitable for trimming of sheets due to its short cycle time. Development of short-cycle manufacturing techniques for carbon fiber–reinforced thermoplastics (CFRTP) is highly demanded; however, the practical use and the study of the shear cutting are limited; thus, the knowledge of its mechanism and process parameters is limited. This study experimentally investigated the deformation behavior during shear cutting and the effect of process parameters on the cut-end profile. From the shearing stress curve and the high-speed video image, we found the bending phase, the shearing phase, and the fracturing phase in the cutting process. It was assumed that the transition from the shear to the fracturing occurred when the tensile stress act in the surface layer of the residual thickness exceeds the tensile strength of the fiber layer. The clearance influenced on the inclination of the sheared face; however, it did not affect the areal fraction of the sheared face in the cut-end. The tool with a small edge angle increased the area of the sheared face. The shallow angle between the fibers and the tool led to the uncut fibers. The cutting speed did not affect the cutting behavior and the cut-end profile. These results indicated that the tool design is the dominant factor to control the cutting behavior. These findings provide insight into our understanding of the shear cutting mechanism as well as the development of the optimum tool design.