The 2-m-long tube is made of an elastic-perfectly plastic material as shown. Determine the...

The 2-m-long tube is made of an elastic-perfectly plastic material as shown. Determine the applied torque T that subjects the material at the tube’s outer edge to a shear strain ol γmax = 0.006 rad. What would be the permanent  angle of twist the tube when this torque is removed? Sketch the residual stress distribution in the tube.