Study of the effect of skewed beam-to-column connections on loss of strength in endplate moment connections

Skewed beams may be utilized due to the architectural limitations. The use of skewed beam cause to initiation of torsional moment, in addition to flexural moment, at the connection face. In the beams with end plate connections, the torsional moment creates shear stress at the end plates which in combine with the shear stress due to connection shear force can lead to reduction in the connection frictional strength and the end plates slippage. This paper investigates the slippage of the end plates of skewed beam with rigid connection to columns with end-plates. 122 finite element non-linear models are used to study the end plate moment connections with skewed beams with 10, 20, 30 and 45 degree of deviation in the plan. The results showed that for the beams with low degree of deviation, the addition of one or two rows of bolts is a suitable method for reducing the loss of strength for skewed beams. For high deviation angle of 45 degree the friction strength loss is considerable and so large number of bolts may be required to be added to recover the friction strength loss, which may not be possible due to the geometric limitations of the connection and so it is recommended in the beams with 45 deviation angle other types of connections to be used.