The Static And Dynamic Analysis Of Steel Frame With Semi-rigid Connections

The beam-column connections are usually assumed as fully rigid connections or ideal pin connections during steel frame analysis. This idealized assumption may make the process of analysis and design simplified, but it could not reflect the real condition of structure, which makes the calculating results with errors, even gets false conclusions.A large number of welded steel frames experienced brittle breakages at the rigid beam-to-beam connections during the Northridge earthquake in 1994 and Kobe earthquake in 1995. A lot of theories and practices confirm that, beam-column connections are semi-rigid. Because the semi-rigid connection increases structural horizontal displacement, it is necessary to consider of the second order effect. This makes people pay more attention to the research of seismic property of steel frames with semi-rigid connections.This paper derived finite element stiffness matrix, mass matrix and damp matrix by using modified type function of beam unit with semi-rigid connection, and established finite element equation. The finite element software (SAP2000) is used to analyze three steel frames with different connection stiffness, from the aspect of second order elastic static analysis, plastic static analysis, modal analysis and dynamic time-history analysis. The target of this paper is to clarify the relation between connection stiffness and internal force, deformation. So as to provide a reference for future research and calculation.