STABILITY OF SPACE FRAMES WITH SEMI- RIGID CONNECTIONS

Abstract

The thesis presents the stability functions for three-dimensional beam- column element, taking into consideration the variation of rigid i ty of the connection according to its type, in order to study the elasti c stability of space frames. Types of connections to be considered i n the present study are totally rigid or semi rigid connections.

The stability functions are presented in their explicit form. The:r, in corporate the effect of non-linearties due to changes in the structme s geometry and changes in the rigidity of the connecti on. A non-l inear stiffness matrix of a beam- column wi th semi rigid connection is also presented. A computer algorithm is developed, based on the mathematical model i n order to obtain the critical buckling load of space frames with semi rigi d connections.

The thesis is devoted to the following main objecti ves: 1. Pred iction of the cri tical buckling loads of space frame with semi- rigid connections, taking into consideration the effect of semi- rigidity of the connections, type of the connections, the ad d itional effect of axia l deformation. 2. The theory of multiple which is valid for plane and space fran1es wi th rigid connections is also valid for the semi- rigid concept wi th the assumption that the all of connections have the same value offixity factors.