The reduced beam section (RBS) connections are used to improve the seismic behavior of rigid connections. The brittle failure and lateral-torsional buckling are the drawbacks of these connections. Drilled flange connections (DFC) are one of the novel configurations of RBS connections. This form of the reduction in beam section can reduce the probability of local buckling, however, the tearing of the beam flange between the drilled holes are the drawbacks of these connections. By implementation proper arrangements of holes and notches, more uniform strain distribution may be made in welds and drilled flanges. The experimental studies were conducted on a welded unreinforced flange (WUF) connection and suggested a sample of drilled flange connection with combined circular holes and notches (CDFC). The results of experimental studies were used to validate the analytical models. To evaluate the seismic performance of different arrangements of the flange drilling, various analytical models were prepared and their behavioral indexes were compared. Results of the analytical studies revealed that by applying the proper drilling pattern, the potential brittle failure, and local buckling of the drilled zone of DFC connections would be reduced. Among the studied arrangements (i.e., WUF, RBS, DFCs with inclined, parallel and combined notches and holes drilling patterns), CDFC with combined notches and holes drilling patterns performed better than the other connections, and Remarkable reductions of damage indexes were observed in connection. By implementing this pattern, the equivalent plastic strain would be reduced up to 71.1% in groove welds comparing to the conventional RBS connections.

减小梁截面（RBS）连接用于改善刚性连接的抗震性能。这些连接的缺点是脆性破坏和横向扭转屈曲。钻孔法兰连接（DFC）是RBS连接的新颖配置之一。梁截面减小的这种形式可以减小局部屈曲的可能性，但是，钻孔之间的梁凸缘的撕裂是这些连接的缺点。通过实施孔和凹口的适当布置，可以在焊缝和钻孔法兰中形成更均匀的应变分布。对焊接的非增强法兰（WUF）连接进行了实验研究，并提出了带有组合圆孔和凹口（CDFC）的钻孔法兰连接的样本。实验研究的结果用于验证分析模型。为了评估法兰钻孔的不同布置的抗震性能，准备了各种分析模型并比较了它们的行为指标。分析研究的结果表明，通过应用适当的钻孔模式，可以减少DFC连接的钻孔区域的潜在脆性破坏和局部屈曲。在所研究的布置中（即WUF，RBS，具有倾斜，平行和组合的缺口和钻孔模式的DFC），具有组合的缺口和钻孔模式的CDFC的性能优于其他连接，并且在连接中观察到损坏指数显着降低。通过实施此模式，等效塑性应变将降低到71。