8604x
001622
2020-02-26

Stability Analysis of Column Under Axial Force and Bending

In this technical article, a hinged column with a centrally acting axial force and a line load acting on the strong axis will be designed by means of the RF-/STEEL EC3 add-on module according to EN 1993-1-1.

The system assumptions, loadings, internal forces, and cross-section design were explained in an earlier article and are, therefore, not discussed again.

Design Under Axial Force and Bending Moment According to EN 1993-1-1, 6.3.3 [1]

Components subjected to bending and compression usually have to fulfill the following requirements.

Flexural buckling design:

Lateral-torsional buckling design:

Flexural Buckling Design Around the Minor Axis

The effective length of the hinged column is Lcr = 6.50 m.

According to EN 1993-1-1, 6.3.1.2:

Selection of a buckling curve according to Table 6.2:

Instability perpendicular to the z-axis: Buckling stress curve BSCz: c

Table 6.1 shows the imperfection factor α = 0.49.

For I, H, and rectangular hollow cross-sections that are only subjected to compression and bending, the coefficient kzy = 0 may be assumed.

This results in the design as follows:

→ Design is fulfilled.

Lateral-Torsional Buckling Design

The effective length of the hinged column is Lcr = 6.50 m.

According to EN 1993-1-1, 6.3.1.2:

Effective length according to Table 6.2:

Instability perpendicular to the y-axis: Buckling stress curve BSCz: b
Table 6.1 shows the imperfection factor α = 0.34.

Interaction factor according to Annex B, Table B1:

Equivalent moment factor Cmy according to Table B.3:

According to EN 1993-1-1, 6.3.2.3:

According to EN 1993-1-1, Tab. 6.5:

→ Lateral-torsional buckling curve BCLT: b

According to EN 1993-1-1, Tab. 6.3:

C1 and C2 from Table 3.2 NCCI: Elastic critical torsional buckling moment [5] (compatible additional documents to Eurocode 3):
C1 = 1.127
C2 = 0.454

Distance from load application point to shear center zg = 18 cm.

According to EN 1993-1-1, Tab. 6.7:

Buckling design around the major axis:

Buckling design around the minor axis:

→ Checks fulfilled.


Author

Ms. Matula provides technical support for our customers.

Links
References
  1. Eurocode 3: Bemessung und Konstruktion von Stahlbauten − Teil 1-1: Allgemeine Bemessungsregeln und Regeln für den Hochbau. Beuth Verlag GmbH, Berlin, 2010
  2. Handbuch RF-/STAHL EC3. Tiefenbach: Dlubal Software, Juni 2020.
  3. Albert, A.: Schneider - Bautabellen für Ingenieure mit Berechnungshinweisen und Beispielen, 23. Auflage. Köln: Bundesanzeiger, 2018
  4. Kuhlmann, U.; Feldmann, M.; Lindner, J.; Müller, C.; Stroetmann, R.: Eurocode 3 Bemessung und Konstruktion von Stahlbauten - Band 1: Allgemeine Regeln und Hochbau - DIN EN 1993-1-1 mit Nationalem Anhang, Kommentar und Beispiele. Berlin: Beuth, 2014
  5. Bureau, A.: NCCI: Elastisches kritisches Biegedrillknickmoment. Aachen: RWTH, 2010
Downloads