Oblique machining of uni directional carbon fiber reinforced polymer composites

Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Mechanical Engineering.Composite materials have a wide range of applications in aerospace and automotive industries due to the advantage of their tailorability when manufacturing. These materials are manufactured near net shape but post-production machining is required where it cannot be avoided like holes, cutouts and doors to achieve dimensional accuracies and for further assemblies. Oblique machining is one of the important processes as to achieve the above. The machining of composites is different from that of metals due to the anisotropic and inhomogeneity of the material. Because of this nature the machining process becomes complicated. The fiber being abrasive in nature and matrix being soft and weak produce fluctuating forces and make difficult for the cutting process causing tool wear. This research hence concentrates on the oblique machining of Uni-directional carbon fiber reinforced polymer composites (UD-CFRP). The oblique cutting of these UD-CFRP‟s are carried out at different rake angles and at different fiber orientations i.e. from 0 to 180 to predict the different forces. These results are compared with the numerical results where a finite element model is modeled for these different conditions and are compared with the experimental results. The oblique machining is a 3-dimensional process unlike the orthogonal machining which is a 2-dimensional process. The finite element model is modeled as a single-phase system by considering the material to be equivalent homogeneous material for analysis purpose, which simplifies for force prediction. The results from the experiments and the finite element analysis can be used for further analysis where multiple layers of composite laminates are used with different fiber orientations. The results can also be used to predict the forces for drilling process by considering the drilling process to be combination of the oblique cutting at each point