What is understood as torsional buckling?
Torsional bucklling due to Additional forces in deformed state that lead to torsion. Happens only to double symmetric cross-sections (others will also flex out of plane)
Give the torsional buckling differential equation
Ip - Polar Moment of Inertia
It - Torsional Moment of Inertia
(They are the same for closed circular profiles)
EIww - Warping stiffness (stiffness, ofbending into the torsional direction)
EIww bending marked:
What is understood as warping? (Wölbkrafttorsion)
Warping describes a beam moving out of plane due to Torsion
What is understood as Flexual torsional buckling?
As soon as a profile is not double symmetric (shear center-center of torsion is not equal to the center of gravity) a profile will experience a combined buckling of Flexural buckling and Torsional buckling.
How are the differential equations coupled for flexural torsional buckling?
The two Bending Differential Equations are also coupled to the Torsional angle
The torsional equation is also coupled to the different bending deflections
All coupling depends on the excentricity of the shear center —> make that 0, remove coupling
How is the buckling load described for an arbitrary profile with ez and ey?
How does the buckling mode look?
If fully coupled, once buckling occurs, all buckling modes will arise simultaniously.
How does the flexural torsional buckling load looks for a doubly symmetric cross - section?
To solve, every bracket can be equated to zero, leading to:
How does an equivalent to the elastic foundation looks like for torsional buckling?
What is Torsional Buckling in German?
Drillknicken
How can Flexural Torsional Buckling (Biegedrillknicken) be avoided?
Modify the profile (goal: remove ez and ey —> Doubly symmetric profile)
Modify the loading point so that the load is applied in the shear center (Kraftangriffspunkt in Schubmittelpunkt verschieben)
Last changed10 months ago
