This Torsion Stress vCalc equation computes the stress in a circular solid or thick-walled shaft.  A thick-walled shaft is defined relative to the radius of the shaft such that wall thickness t > 0.1r.

Inputs

This equation computes the torsion stress¹ as a function of the following factors:

• T - torque (force applied at some distance from the axis of rotation)
• r - radius of torque
• J - polar moment of inertia (a metric predicting an object's ability to resist a force causing rotation)

1. ^ Fundamentals of Engineering. 8th edition, 2nd Revision.  National Council of Examiners for Engineering and Surveying (NCEES) -- 2001. ISBN 978-1-932613-59-9.  pg 36