Simplified design equations for Plate-to-CHS T and X joints for use in codes

This paper deals with revised, simplified, consistent equations for plate-to-Circular Hollow Section (CHS) joints for inclusion in codes. After a short review of the background to these resistance equations in the current consolidated version of EN 1993-1-8 and those in ISO 14346, the background to these simplified new equations is discussed. The equations for Plate-to-Circular Hollow Section T and X joints (called TP and XP joints respectively) in the current EN 1993-1-8 are based on experimental data available up to 1991. They are further related to the equations for CHS T and X joints. Most of the data used are based on the ultimate joint resistance. A similar approach is used for the TP and XP equations in ISO 14346, but these are related to the updated equations for CHS T and X joints.
Since the drafting of ISO 14346, new consistent numerical data from Voth became available where the resistance is not only based on the ultimate resistance but also takes the 3 %d0 joint deformation limit into account.
The new equations in prEN 1993-1-8 are based on the Voth data, the de Winkel data and the Voth-Packer equations, but use a simplified uniform presentation which permits one to relate joints with an I, H and RHS brace-to-CHS chord to these basic equations. Furthermore, the presented equations are based on the case of axial compression load in the plate, which is the lower bound of the compression and tension load cases.