Steel Frames with Nonlinear Connections

Various simplifying assumptions, commonly used in the design of unbraced multistory steel building frames, are explored. An analysis program was developed to account for the nonlinear flexibility of the girder-column connections as well as for the response to variable load histories. Analyses were performed on three different structures. The results show the importance of including actual connection behavior for realistic prediction of sway and internal forces. The possibility of the occurrence of alternating connection plasticity is also pointed out. The inclusion of linearly-elastic connection flexibilities in the analysis appears to lead to very satisfactory results.