9520218 Yura Design guidelines will be developed for connections between concrete filled steel tubular columns and steel beams in large structural systems suitable for seismic applications. The main variables included in the research are square and round tubes and various degrees of strengthening beyond the plain filled tube detail. The strengthening will concentrate on utilizing the strength of concrete within the panel zone. At least 8 reasonably full size test specimens will be designed and tested, first monotonically, then cyclically. The object will be to develop practical connections for seismic area that minimize welding and stiffener details. Since there are currently no design guidelines for such connections, the research is vital to the development of hybrid and composite civil infrastructure systems. This is a project supported under CIS solicitation "Research on aomposite NSF - 94-154. ***
