Numerical analysis of thin walled beams with internal unbonded cables by the Ritz method

The authors analyze the behavior of thin walled beams crossed by internal stretched cables anchored at their ends but free to slip without friction along their path, by using a previously presented model. The guidelines for the numerical solution of the linear elastic problem and the stability analysis are presented in general form and applied to a class of problems of technical interest. The numerical analysis examines the case of simply supported beam with symmetric open cross section, crossed by a cable placed on rectilinear or parabolic paths lying in the symmetry plane, assuming as problem variables the beam stiffness, the parameters describing the cable path and the cable traction force. This permitted evidencing some aspects of the problem of interest in structural engineering, by showing the relations between stress increments of beam and cable under external force and the complex relations arising between beam bending, torsional and shear stiffness, cable path, cable traction force and external load in the stability analysis.