17. The following data was obtained from orthogonal turning of PEEK and short- fiber-reinforced PEEK (C/PEEK, V = 0.3) [24]. Refer to Fig. 2.2 for definition of cutting variables. The cutting conditions are v = 100m/min, depth of cut ap = 2.0mm, k = 90, =0, Y = 7. f (mm/rev) PEEK C/PEEK ao/ac Fc (N) Ft (N) ao/ac Fc (N) F (N) 0.05 1.43 39.29 0.10 1.35 66.14 0.15 1.33 0.20 1.30 18.14 1.38 21.42 1.32 92.51 24.88 1.31 118.82 28.41 1.17 41.76 33.52 68.06 40.10 90.69 44.41 111.68 47.93 Calculate the following for each cutting condition, for both PEEK and C/PEEK: (a) Shear plane angle, (b) Theoretical shear strain in the chip (c) Theoretical shear stress and normal stress in the shear plane (d) Friction angle (e) Specific cutting energy, ps, specific shear energy, us, specific frictional energy, uf, and the difference [ps - (us +uf)]. Discuss the results. (f) Plot shear plane angle vs. (-) for both materials (g) Plot shear stress and normal stress in the shear plane vs. feed rate for both materials (h) Plot shear strain vs. feed rate for both materials (i) Using the results from (f), (h), and (i), discuss the applicability of the shear plane theory to the machining of PEEK and C-PEEK, highlighting the differences, if any, between the two materials.