Thin Sections in Torsion: The Direct Stresses Developed in Open Sections with One End Subject to Constraint

WHEN a thin‐walled hollow cylinder is subjected to torsion, it is generally assumed that, if the length is great compared with the linear dimensions of the section, direct stresses—in the direction of the axis of the cylinder—are absent, and that the shear stress is everywhere proportional to the thickness. The shear stress q is then calculated from the familiar Batho formula: