Stability and vibration of rods under follower forces; BCOP method

A procedure is illustrated in order to study beams with variable cross-sections subjected to sub-follower forces. The analysis is based on a variational approach with Boundary Characteristic Orthogonal Polynomials (BCOP) are chosen as trial functions polynomial trial functions, employed by the same authors for beams with constant cross sections [9]. The instability regions by divergence and flutter are examined in some detail, so allowing to determine the range of applicability of the static instability criterion. Some numerical examples are compared with other classical results from the bibliography, so confirming the goodness of the proposed approach.