Experimental comparison between threaded‐bars and single‐bolts end plate asymmetrical steel joints

End plate beam‐column bolted joints are widely used in the field of steel structures. The usual configuration consists of individual bolts that join the end plate of the beam with the column flange. Usually, the use of stiffeners is needed in this type of joints, in order to reinforce the tension and compression zones of the column web, and to avoid local buckling problems.

This configuration, applied to asymmetric connections, gives rise to the appearance of shear stresses in the column web, even with symmetric loading conditions on both sides of the connection.

The method proposed in this work to improve the behavior of end plate asymmetrical steel joints, without using welded stiffeners (which significantly increases the cost of the joint), consists in using threaded bars as joining elements, instead of single bolts. Threaded bars have several purposes: to create the joint itself, to reinforce the tension and compression zones, and to reduce the shear stresses in the column web panel.

In the present work, two end plate steel joints made up of an HEA200 column, and IPE200 and IPE300 beams have been tested. One of them with threaded bars with double nuts (internal and external) in the traction and compression zones, and the other one with single bolts.

Symmetrical forces have been applied at the ends of the beams, subjecting the joints to symmetrical bending moments on both sides of the connection. The tests have been instrumented through the use of load cells, displacement sensors and inclinometers. The results show an important increase in the stiffness and the resistance of the joint with threaded bars, compared with the single bolts joint.

This work will serve as the basis for the calibration of the corresponding finite element models, and the subsequent parametric study of this type of joints.