Stability of semi-rigid space frames

Abstract

This paper presents a modified stiffness matrix method for obtaining the elastic buckling load of semi-rigid space frames. This is an extension of the method applied to semi-rigid plane frames. Again the method, besides accounting for the partial rigidity of the joints, also considers the effects of flexure on axial stiffness, geometric changes and the P-Δ effect. A computer program has been written to carry out the doubly iterative process of finding the buckling load. A parametric study on the effect of rigidity of various joints and also bracings on a single-bay single-storey space frame is made. Also, a space frame, simulating a simple scaffold, is studied for the effect of the rigidity of the bracings for three cases of loadings. The results of the parametric studies are presented in the form of charts. © 1987.