Buckling Eigenmodes

The ideal buckling load according to Petersen [1] is PKi = 56.4 kN.
The ideal buckling load according to Petersen [1] is PKi = 56.4 kN.

The following compression beam is fixed at one end and subjected to load according to Euler case 1. The profile and system dimensions are illustrated below. The beam is made of construction steel St 37. The load is applied at the center of mass.

For the system detailed above, the FEM calculation delivers the following results for the first 4 buckling eigenmodes. Influences such as shear strain and warping are taken into account.

  • Buckling mode 1, load factor = 54.14 (torsional buckling)
    Buckling mode 1, load factor = 54.14 (torsional buckling)
  • Buckling mode 2, load factor = 190.52 (buckling about the z-axis of the cross-section)
    Buckling mode 2, load factor = 190.52 (buckling about the z-axis of the cross-section)
  • Buckling mode 3, load factor = 345.88 (buckling about the y-axis of the cross-section)
    Buckling mode 3, load factor = 345.88 (buckling about the y-axis of the cross-section)
  • Buckling mode 4, load factor = 422.61 (buckling about the z-axis, 2nd eigenmode)
    Buckling mode 4, load factor = 422.61 (buckling about the z-axis, 2nd eigenmode)
  • Shell buckling of a tank
    Shell buckling of a tank

[1] Petersen, C.
Statik und Stabilität der Baukonstruktionen (Statics and Stability of Constuctions). Vieweg Verlag, Braunschweig 1980.

[2] Rubin, H.; Aminbaghai, M.
Ein Stabilitätsproblem mit Überraschungen (A Stability Problem with Surprises).
Stahlbau 66, Issue 5, pp. 271 - 276. Verlag Ernst & Sohn, Berlin 1997.