Seismic behaviour of semi-rigid steel frames

This paper deals with aspects of the performance and design of steel frames with semi-rigid connections under earthquake loading conditions. Current evidence on the feasibility of this type of structure for seismic design is discussed. This is followed by a description of a testing programme on two-storey frames with rigid and semi-rigid beam-to-column connections. A brief account of the results from five monotonic, cyclic and pseudo-dynamic tests is presented. An analytical component-based model is verified in comparison with the tests; static and dynamic response comparisons are undertaken. The model is used to investigate further the effect of semi-rigid connections on the member as well as the frame behaviour. It is shown from both the experimental and analytical investigations that semi-rigid frames exhibit ductile and stable hysteretic behaviour and may be used effectively in earthquake-resistant design.