The hollow torsion member shown in Figure P6.39 has thickness t1 for half of its mean circ...

The hollow torsion member shown in Figure P6.39 has thickness t1 for half of its mean circumference and thickness t2for the other half. Show that the shear flow is constant around the mean circumference by considering the equilibrium of an element of length dz and arc length (r dθ) at the junction of thicknesses t1 and t2. Neglect stress concentrations.

FIGURE P6.39