(b) The solid shaft is subjected to a torque, bending moment, and shear force as shown in Figure 4. Determine the principal stresses acting at points A and B.(16%)

(b) 下圖1-b所示的組件由橫截面積為400 mm²的鋁管AB組成。一直徑為10 mm 的鋼桿連接到剛性軸環上,並穿過管子。如果對鋼桿施加了80 kN 的拉伸載荷,試決定鋼桿端 C 的位移。已知鋼桿和鋁管的楊氏係數分別為 Est = 200 GPa, Eal = 70 GPa。(15%)