Torsional strength of nickel steel and duralumin tubing as affected by the ratio of diameter to gage thickness

N. S. Otey
April, 1924

This investigation was made at the request of the Bureau of Aeronautics. Since the ordinary torsion formula is based on elastic resistance to deformation, it is inaccurate for determination of ultimate stresses in thin wall tubing subjected to torsional loads. It has been found that the torsional modulus of rupture varies with the ratio of diameter to gage thickness and the object of these tests was to determine the extent of these variations for subject materials. This is somewhat of a prorogation of work done by the Army Air Service at McCook Field.

An Adobe Acrobat (PDF) file of the entire report: