Today connections are playing an important role in the steel frames subjected to lateral seismic loading. The steel extended end-plate moment connection can play an important role in the steel frame when subjected to seismic loadings. In the past, this type of connection has been under investigation mainly when it was subjected to monotonic loading. After major recent earthquakes and failure of number of traditionally practiced moment connections in US, it seems that the extended end-plate moment connections can be qualified as a suitable semi rigid type connection to be used in the heavy steel frames.
In this article, the seismic behavior of the extended moment connection is investigated. Using the nonlinear finite element method of analysis and with the help of yield line analysis, the behavior of the connection, with the emphasis on the column depth and end-plate thickness effecting on the panel zone as well as the connection as a whole, is obtained and then the results are compared with those obtained from tests by other researchers. Plastic moment versus plastic rotation hysteresis, stress contours of the pertinent part of the connections and displacements are part of the results of this study. The difficulties arising in modeling and analysis technique, exists in such connection, is also discussed.
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