Analytical Modeling of Beam-Column Joints of Composite SRC Frame Systems
Joseph M. Bracci, Ali 0. Atahan, and Sashi K. Kunnath
Appears on pages(s):
Analytical chemistry; composite construction; earthquake-resistant
structures; joints; shear properties; structural analysis
Equivalent macromodel-based analytical tools, comprised of flexibility-based element models, are used to accurately represent the non-linear moment-curvature (force-deformation) response characteristics in structural systems using columns of reinforced concrete (RC) or composite steel sections encased in reinforced concrete (SRC), structural steel beams, and composite beam-column joints. To facilitate the modeling of inelastic deformations in joint regions, a panel element capable of representing joint shear distortions and joint bearing deformations was developed and incorporated into an existing computer program, IDARC. The inelastic shear-deformation characteristics of the joint panel were partly established from guidelines published by an ASCE Task Committee (1). Various hysteretic control parameters for members of the subassemblage, such as strength degradation, stiffness deterioration, and pinching (slip), were quantified based on observed experimental response. Potential failure modes in the steel beam, RC or SRC column, and composite joint of the frame subassemblage can be represented in the proposed formulation. Experimental subassemblage testing performed at Cornell University (2) was used to validate the analytical platform. It is shown that the revised IDARC program can be used for seismic evaluation of composite structures and for development of design guidelines to ensure desirable mechanisms in RCBRC structures.