Stiffness of equal width welded I‐beam to RHS column connection

Resum

Despite some recent efforts, the use of mechanical approaches like the component method for the rotational stiffness of connections is still not present in the design codes for hollow sections. In addition, the easiest way to obtain semi-rigid connections with high rotational stiffness or even rigid ones with I beams and RHS columns is to design both members with the same width. In this way, loads are transferred almost directly from the beam flanges to the side walls of the RHS, avoiding the high rotations due to the bending of the front face of the RHS. Considering all this, some experimental tests have been used by the authors to validate a finite element model that simulates equal width connections in which the component ‘lateral faces of RHS’ under transverse forces was the main source of beam rotation. This was selected as the most important component to be considered in the welded joints between I beams and RHS columns when they have the same width. Then, some different analytical approaches for its stiffness have been assessed by comparing them with the experimental and numerical results. This work finally proposes a design equation for the ‘lateral faces of RHS in tension or compression’ in order to be applied in a future unified proposal for the component method including hollow sections. In addition, a rotational stiffness approach for the equal width welded I-to-RHS connections has been directly derived from this.