seismic behavior of drilled beam section in moment connections

Reduced beam section (rbs) and drilled beam section (dbs) are seismic moment resistant frame connections, introduced after 1994 northridge earthquake. rbs connection has been tested under cyclic loading and showed acceptable performance. in this paper, seismic behavior of drilled beam section (dbs) connection is studied numerically using finite element method. a drilled beam section of a cantilever h-beam has been subjected to cyclic loading at its free end and studied for its optimal shapes. 62 samples of dbs connections have been modeled and studied under cyclic and pushover loadings. based on the results obtained in this research, the connection shows its positive seismic behavior if the biggest hole is near the column face and its diameter decreases as the holes move away from the column face. in this research the effects of dimensions, position and number of holes are investigated using von mises stress and elastic strain criteria under cyclic and monotonic loadings. in this drilled beam the smaller holes shift plastic hinges out of the connection zone.