Nonlinear seismic response analysis of steel-concrete composite frames

Frame finite-element models permit obtaining, at moderate computational cost, significant
information on the dynamic response behavior of steel–concrete composite (SCC) frame
structures. As an extension of conventional monolithic beam models, composite beams with
deformable shear connection were specifically introduced and adopted for the analysis of SCC
beams, in which the flexible shear connection allows development of partial composite action
influencing structural deformation and distribution of stresses. The use of beams with deformable
shear connection in the analysis of frame structures raises very specific modeling issues, such as
the characterization of the cyclic behavior of the deformable shear connection and the assembly
of composite beam elements with conventional beam–column elements. In addition, the effects on
the dynamic response of SCC frame structures of various factors, such as the shear connection
boundary conditions and the mass distribution between the two components of the composite
beam, are still not clear and deserve more investigation. The object of this paper is to provide
deeper insight into the natural vibration properties and nonlinear seismic response behavior of
SCC frame structures and how they are influenced by various modeling assumptions