260
7 Torsion of Prismatic Bars
Fig. 7.23 Aeroplane elevator
Fig. 7.24 Three cell tube
section
11. Show that for the same twist, the elliptic section has a great shearing stress than
the inscribed circular section (radius equal to the minor axis b of the ellipse)
that takes the greater torque for the same allowable stress.
12. Find the expressions for the shear stresses in a tube of the section shown in
Fig. 7.24, taking wall thickness as t uniform throughout.