Large Deformation of Inelastic Large Space Frame. I: Analysis

Abstract

A member model divided into subelements along the member axis with end fibers is developed for material and geometrical nonlinear analysis of a space frame structure. The fiber stress-strain relationship is an extended Ramberg-Osgood model. To assume appropriate stiffness on the alternative of fiber loading or unloading, a trial stiffness selection procedure is presented. Analytical increments for an overall frame are set relatively large for application to a frame with many members. Analytical results for a simple truss agreed well with the experimental results and simulated the complicated behavior of a web member, which first buckled slightly, then was unloaded, and finally rebuckled in another mode under a monotonous loading.