Influence of Shear Connections on Stability Analysis and Consideration

For structural reasons, shear connections usually include fin plates or flange angles. Main and secondary beams arranged on the top edge require notching or long fin plates. Hinged end plate connections are often welded to the web.

In stability analysis, all these connection layouts are considered not as lateral and torsional restraints, but as torsional springs.

RF-/STEEL EC3 offers the following options to take this into account:
~ When using the Equivalent Member Method, you can either adjust the lateral-torsional buckling length L_w in Window 1.5 or 1.6 (see [3] and [4]), or enter the elastic critical moment for lateral-torsional buckling directly (see [1], [2], and [3]). To do this, change the determination of the elastic critical moment for LTB in the "Details" dialog box, "Stability" tab.
~ When using the General Method, you can enter the torsional spring φ_X' directly in Window 1.7. For notes on the torsional spring calculation, see [1] and [3].

References:
[1] Kuhlmann, Feldmann, Lindner, & Stroetmann. (2014). Eurocode 3 – DIN EN 1993-1-1 with NA – Commentary and Examples, (1st ed.). Beuth Verlag, Ernst & Sohn, p. III – 147 ff.
[2] Kuhlmann (ed.). (2009). Stahlbau-Kalender 2009, p. 335 ff. Ernst & Sohn.
[3] Mensinger, & Möller. (2014). Einfluss von Querkraftanschlüssen auf das Biegedrillknicken von Einfeldträgern – Teil 2, Stahlbau 83(3), p. 174 ff.
[4] The Steel Construction Institute and The British Constructional Steelwork Association. (2011). Simple Joints to Eurocode 3, p. 20.

Links

Steel Structural Analysis & Design Software

;