sentences:  The maximum shear stress, therefore, occurs at the edge of the midpoint of the stretched cross section, and is equal to formula_1, where T is the torque applied, b is the length of the stretched cross section, and t is the thickness of the cross section.It can be shown that the differential equation for the deflection surface of a homogeneous membrane, subjected to uniform lateral pressure and with uniform surface tension and with the same outline as that of the cross section of a bar under torsion, has the same form as that governing the stress distribution over the cross section of a bar under torsion.This analogy was originally proposed by Ludwig Prandtl in 1903.