An Analytical Study on Shear Transferring in Beam to Column Connections of Welded Steel Moment Frames

Beam-column connections in steel frames have been traditionally designed by using classical Euler-Bernoulli beam theory which leads to the assumption that the flanges transfer moment while the web connection primarily resists the shear forces. On the other hand، lessons from the past earthquakes imply that some steel connections with weak web connections have adequate performance in transferring shear forces. It is probable that the truss mechanism in such systems helps in transferring shear forces. This mechanism can work without web connection to column face. This work presents the results of finite element analyses of three types of welded beam-column connections subjected to bending and shear forces of beam in the range of nonlinear behavior of materials and inelastic buckling of the cross section. In the first and second model، connection is based on welding flanges of the beam to the face of the column and in the third model; both web and flanges of the beam are connected to the column. The location of plastic hinge of the beam from the face of the column is studied in each case. It is observed that shear transferring capacity of the first and second models are much higher than expected based on the classical Euler-Bernoulli beam theory.