Eurocodes 3 connection design

For each steel connection, Autodesk Advance Steel provides an interactive window that allows users to define the desired parameters.

All changes made in this window can be viewed in real time. Moreover, the collision check tool warns when connection elements overlap, and also notifies the user whether there is enough space for a wrench to fit between the bolts.

The beam to column knee of frame bolted with haunch is a typical connection, commonly used between steel structural elements. After defining the connection parameters and efforts based on the connection calculation, users can easily check if the steel connection follows Eurocodes 3 rules.

Global analysis

The global analysis can be done only if the defined hypotheses are compatible with the predictable behavior of steel connections. For moment distributions, the beam to column connections are usually modeled as fully hinged and fully fixed. Actually, the connection behavior is in between these two extremes. For this reason, Eurocodes 3 specifies an intermediary type of connection: the semi-rigid connection.

Starting from the moment - rotation M - F behavior curve of a connection, three main characteristics can be distinguished:

Young modulus or tangent modulus for a given moment, M_Sd
Design resistance moment, M_Rd
A rotation capacity Φ_Cd greater than M_Rd moment

Taking into account these characteristics, beam to column connections are classified as a function of stiffness and resistance.
According to stiffness, three areas can be distinguished on M - Φ diagram, based on M_pl - Φ_pl beam characteristics. These areas are determined by the initial K₀ stiffness of the steel connection.