| After the 1994 Northridge earthquake event, the once belief of the reliable ductility capability of the widely used bolted-web-welded-flange (BWWF) connections has been shattered. Intensive follow-up post-earthquake investigations as well as research activities revealed an urge in modifying this typical BWWF connection for new construction. Among many modification approaches, strengthening the typical BWWF connection with cover plates has emerged as a very promising method. While limited laboratory tests had shown its satisfactory performances, this research however aims to examine further limitations in the applications of strengthened cover-plate connections through limited parametric studies in both local (connection assemblage) and global (whole structure) levels. The studies are implemented through computerized analyses. Reliable solutions necessitate the need for the calibrations of all analysis models locally and globally. Information obtained from the local behaviors of reliable strengthened cover-plate models assist in postulating as well as substantiating the modeling assumptions of the simplified structural models that are used in the seismic assessments of all frames. The analysis results show that frames with cover-plate connections can provide complete protection against brittle failure at the connection joints under severe ground motions. |
