“…As to the fundamental expressions of stresses and displacements of a circular hollow tube subjected to torsion, based on the theory of Saint Venant, it is well known that the stress distribution inside the layer body is quite simple: only longitudinal shear stress will be induced if the material anisotropy is not beyond the cylindrically orthotropic [7,8]. And, on this basis, they can be determined using a semi-inverse method, such as [6,[9][10][11] among others, and therefore most of the results express the stress distributions no matter whether on the end surfaces or any cross section are of the same. The expressions obtained through relaxing the boundary effects cannot correctly reflect the real stress and displacement distributions near the boundary, except for the particular boundary conditions coinciding with the Saint Venant distributions.…”