Torsional Loading Theory (short version)

 

Stress Element with 0^o Orientation

A state of pure shear stress exists for the element shown.  The normal stresses are zero.

 

Stress Elements with 0^o and 45^o Orientations

 

Mohr's Circle for Torsion

 

Ideal Linear Elastic, Perfectly Plastic Behavior

 

Torsional Stress Distribution

Surface Yield Impending	Partial Plastic, Partial Elastic	Fully Plastic

 

Surface Yield Impending Case:

(Elastic Material Behavior)

 

Fully Plastic Case:

 

Actual Torque vs. Angle of Twist Diagram

Slope of the linear portion of the diagram is

For linear elastic behavior

Hence

 

Equations Summary