Buckling Analysis of Elastic Space Rods under Torsional Moment

Abstract

The buckling behavior of elastic space rods under torsional moment is studied theoretically. A consistent method is developed to identify the buckling torsional moment as well as to trace the postbuckling path. Since this buckling phenomenon accompanies a nonlinear interaction between flexural deformation and torsional deformation, a special consideration has to be made in the treatment of finite rotations in three-dimensional space. First, a buckling analysis based on a rigorous nonlinear beam theory is developed to identify the bifurcation moment. This analysis precisely takes into account the prebuckling torsional deformations as well as the effect of axial compressive force. Next, the postbuckling behavior is analyzed by the transfer matrix technique, which was previously presented by the writers. With this method, the buckling and postbuckling behavior of space rods under torsional moment are examined with an emphasis on the effect of cross-sectional shapes as well as axial compressive force.