A computer aided analysis of a steel space truss in fire: Fid-Bau Portal

A computer aided analysis of a steel space truss in fire

Mwakali, J.A.

In order for a structural member to be able to carry its load during after a fire its size may need to be greater than that which is dictated by purely structural considerations. The good performance of space structures in service, largely because of their high rigidity, is impressive. Space structures are therefore used to easily span large uninterrupted distances unthinkable with conventional constructions. However, not much is known about the performance of space structures under fire conditions. As the pace of economic and industrial development in Africa picks speed, it is inevitable that many prestigious structures will be built. Space structural systems are usually good candidates for such constructions. But experience also shows that the frequency of fire outbreaks is relatives high in the more industrialised countries of the world. An outbreak of a fire in a building usually results in high financial and human losses. This concern is manifested in the ever increasing stringency of fire resistance requirements for especially, high-rise buildings. Although space structures are generally used in low-rise large-span constructions, the very prestigious nature of such construction projects means that consideration for their fire requirements is no trivial matter. This paper gives a brief insight into the effects of temperature elevations on a space truss. The finite element method is used to carry out a linear static analysis of a small steel double-layer aid under the influence of temperature elevations. The critical nodal deflections and forces and He equivalent nodal point loads are found for some few temperature elevations above the assumed ambient room temperature of 20 deg C found that temperature elevations have a catastrophic effect on the structure.