A simplified analysis of doubly symmetric tube structures by the finite difference method

Abstract

This paper demonstrates a simple but accurate analytical method usable for the preliminary design stages of doubly symmetric single and double frame-tubes with braces in high-rise structures. The present method is formulated by replacing the tube with an equivalent rod, in which the effects of bending, transverse shear deformation, shear-lag and torsion are considered. The static analysis and free vibration are presented by applying the ordinary finite difference method to the governing equation for a double symmetric tube proposed by Takabatake et al. (1993). The dynamic analysis is taken from modal analysis. Static and dynamic numerical computations are carried out for doubly symmetric single and double frame-tubes with braces. The results obtained from the theory proposed here are in good agreement with results obtained from three-dimensional frame analysis using the FEM codes NASTRAN and DEMOS.