Stress in a Three-Dimensional Truss Column under Torsion

Abstract

To enable the calculation of member stresses in a three-dimensional truss column under torsion, we examined the way in which each element in a matrix equation of equilibrium obtained as a result of statically indeterminate calculation could be expressed in a general manner. To be more precise, by automatically forming equations of equilibrium in a computer by repeated calculation, we formed a calculation program for working out these equations. In order to verify the practicability of this program, we made a comparison between experimental results obtained by means of using models and that of calculations under this program, ascertaining that these two results were in close agreement under various load conditions. In addition, we examined the characteristics of member stress in a three-dimensional truss column under torsion by this program. As a result, there was a clarification on the relation between the number of three dimensional framework stories and member stress, the effect of horizontal diagonal members, the distribution of twisting moment to joints, and other points. Also, it was proven that the conventional Japanese Standard JEC-127 furnishes a very different result from actual conditions.