Experimentally analyzed stability and ductility behaviour of a space-truss roof system

Abstract A space-truss roof-system [1] , was experimentally analysed to determinate the behaviour of this system until collapse. The main aim of the investigation to find what is the stability and ductility behaviour of this system under eccentric and concentric force and to investigate an adequate moment-rotation function to model the behaviour of the truss connections as semi-rigid joints in the numerical model. A symmetrical space-truss section was examined. This system contains thin-walled hollow squared sections as truss bars, and every bar has uniform length. In every joint eight bars are connected by high-strength pre-stressed bolts. Inductive transducers measured the deflections of joints, and strain gauges measured the strains in the investigated bars. Four strain gauges were in the mainly tension members and eight strain gauges were in the mainly compression members, each end of the bars. This paper deals with the detailed investigation of this roof system during the “elastic” range and the collapse.