Prob. 4.5-4. The aluminum-alloy shaft AC in Fig. P4.5-4 (G= 26 GPa) has an 800-mm-long solid segment AB and a 400-mm-long tubular segment BC. The shaft is subjected to the torsional loading shown in the figure. The diameters are d = (do)2 = 50 mm and (d)2 = 20 mm. (a) Determine the maximum shear stress in the shaft, and identify the loca- tion(s) where this maximum shear stress occurs. (b) Determine the angle of rotation at B. B. and the angle of rotation at C. c. (do)2 QB 8 kNm d (1) A 800 mm t 3 kNm x (di)2 C B 400 mm P4.5-4 and P4.5-12 D