Abstract
The three-dimensional rotations of finite magnitude are well known for being out of a linear space, but to be dealt with in the nonlinear field, more generally. Further, in the formulation of variational problems such as the present elastic deformation, the way of describing moments is significantly associated with that for finite rotations. In this paper, according to the theory which has been proposed to decompose a moment into the components in such a manner that the inner products between its components and differentials of the rotation parameters represents the real infinitesimal work, an actual discretization of thin-walled beams will be developed without any restriction on the magnitude of displacements themselves, under the condition of small strains.
