EFFECTS OF SEMI-RIGID GIRDER CONNECTIONS ON THE DYNAMIC RESPONSE OF STEEL STRUCTURES

The nonlinear response of a ten story steel structure with semi-rigid girder connections is studied under conditions of dynamic loading. The dynamic loading used in this study is the north-south component of the may 18, 1940 El Centro, California earthquake. To deal with the complexity of the problem the structure is idealized by a series of equivalent masses, lumped at the floor levels and restrained by weightless members. The physical model used to represent individual members consists of a flexible central beam with springs attached at both ends. All connections have the capability of exhibiting bilinear hysteresis curves. The analysis is accomplished within the general purpose computer program SAP 2000 V 10. Semi-rigid girder connections affect the properties of a structure in three ways: (a) by altering the relative girder to column stiffness, (b) by changing the strength or yield deformation characteristics, and (c) by decreasing the stiffness of the structure. The effects that these variables have on structural response are determined. The ground motion characteristics, intensity, and duration are also investigated.