The analysis and behaviour of composite space frames with profiled steel sheet floors
The objective of this research was to analyse and investigate the behaviour of a composite space frame. The space frame is assembled from individual inverted square-based pyramids. Each pyramid consists of a steelangle section top-tray and diagonals. When the top trays are connected together, they form the top-chord members of a double-angle section connected back to back. The investigation is primarily concerned with the composite section within the space frame system which comprises the top chord members, profiled steel sheeting and a concrete slab. This composite section is also assumed to work as a system of intersecting composite Tbeams. Each composite T-beam comprises of a top chord member, a certain width of profiled steel sheet and a concrete slab. The composite action is ensured by a series of self-tapping screws. The experimental work is based on two-unit space frame specimens. Each specimen represents two adjacent units with their top chord member which carries the highest compressive axial load in the real structure. Each unit is tested in a situation which simulates its position and loading within the real structure. In addition to the composite T-beams being tested, steel struts composed of the top chord member double-angles were tested. In the theoretical section, the real structure is analysed as composite beam elements and thin steel plate elements which all represent the top composite T-beams. The diagonals and the ties were considered as truss elements. A successful method of analysis was developed using matrix and finite element methods resulting in the force distribution and deformations for a full composite space frame. Additionally, the experimental work yielded useful information on the behaviour of composite struts of this type. Recommendations for future work are made. The investigation of the behaviour of the composite T-beams with different locations and numbers of shear connectors together with the analysis of the structure comprise the main part of this work.