Linearized Buckling Analysis
Slender models tend to buckle under axial loading. Buckling is defined
as the sudden deformation which occurs when the stored membrane (axial)
energy is converted into bending energy with no change in the externally
applied loads. Mathematically, when buckling occurs, the stiffness becomes
singular. The Linearized buckling approach, used here, solves an eigenvalue
problem to estimate the critical buckling factors and the associated buckling
mode shapes.
A model can buckle in different shapes under different levels of loading.
The shape the model takes while buckling is called the buckling mode shape
and the loading is called the critical or buckling load. Buckling analysis
calculates a number of modes as requested in the Buckling
dialog. Designers are usually interested in the lowest mode (mode 1) because
it is associated with the lowest critical load. When buckling is the critical
design factor, calculating multiple buckling modes helps in locating the
weak areas of the model. The mode shapes can help you modify the model
or the support system to prevent buckling in a certain mode.
A more vigorous approach to study the behavior of models at and beyond
buckling requires the use of nonlinear design analysis codes.
When to Use Buckling Analysis
Slender parts and assemblies with slender components that are loaded
in the axial direction buckle under relatively small axial loads. Such
structures can fail due to buckling while the stresses are far below critical
levels. For such structures, the buckling load becomes a critical design
factor. Buckling analysis is usually not required for bulky structures
as failure occurs earlier due to high stresses.
Related Topics
Buckling
Load Factor
Performing
Buckling Analysis