BEHAVIOR OF CFT COLUMN-WF BEAM MOMENT CONNECTIONS UNDER SEISMIC LOADING

This paper describes research associated with the seismic behavior of moment connections for concrete filled tube (CFT) column-to-wide flange (WF) steel beam framing systems. The objective of this multiphase research program is to assess the force transfer mechanism in these connections, examining the effect various structural details have on this mechanism, as well as on the connection's strength, stiffness, and ductility. The first phase of the program was devoted to assessing the shear capacity of the panel zone in a CFT column-to-beam connection under simulated seismic lateral load conditions. The results from tests show that a CFT panel zone possesses exceptional ductility, including connections without interior diaphragms. In addition, a capacity equation based on the superposition of the shear strength contribution of the steel tube and concrete core within the panel zone provides a prediction that agrees reasonably well with specimen strength. The second phase of the research program involves full-scale structural connection subassemblage tests. Results from tests show that specimens in which the beams are designed to dissipate energy can have exceptional cyclic ductility. However, connections must be properly detailed to avoid strain concentrations which could lead to fracture. Measured deformations in the column show that a CFT column's initial stiffness is well estimated by transformed section theory. However, interstory drift deformations beyond 0.5% of the story height tend to reduce the stiffness after concrete cracking and debonding of the concrete from the steel tube.

  • Corporate Authors:

    American Concrete Institute

    38800 Country Club Drive
    Farmington Hills, MI  USA  48331
  • Authors:
    • Ricles, J M
    • Lu, L W
    • Sooi, T K
  • Publication Date: 1998

Language

  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 1-36
  • Monograph Title: HYBRID AND COMPOSITE STRUCTURES

Subject/Index Terms

Filing Info

  • Accession Number: 00754751
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Oct 5 1998 12:00AM