Buckling Load Factor
The buckling load factor (BLF)
is the factor of safety against buckling or the ratio of the buckling
loads to the applied loads. The following table illustrates the interpretation
of possible BLF
values:
|
BLF
Value (factor of safety) |
Buckling Status |
Notes |
|
1 < BLF |
Buckling not predicted |
The applied loads are less than the estimated critical loads. Buckling
is not expected. |
|
0 < BLF < 1 |
Buckling predicted |
The applied loads exceed the estimated critical loads. Buckling is expected. |
|
BLF = 1 |
Buckling predicted |
The applied loads are exactly equal to the estimated critical loads.
Buckling is expected. |
|
BLF = -1 |
Buckling not predicted |
The buckling occurs when the directions of the applied loads are all
reversed. For example, if a bar is under tensile load, the BLF should
be negative. The bar will never buckle. |
|
-1 < BLF < 0 |
Buckling not predicted |
Buckling is predicted if you reverse all loads. |
|
BLF < -1 |
Buckling not predicted |
Buckling is not expected even if you reverse all loads. |
Generally, a structure can have both positive
and negative buckling load factors. For example, imagine a cylindrical
vessel under internal pressure supported by columns. The vessel will never
buckle as it is under tension, however the columns may buckle as they
are under compression.
Calculating Buckling Loads
To calculate the buckling load(s)
for a mode, multiply all applied loads by the BLF for that mode. For example, suppose that you applied the
following loads:
and the buckling load factor
(factor of safety) for mode 1 is calculated to be 2.3,
then buckling in mode 1 will occur if you apply:
Related Topics
Linearized
Buckling Analysis
Performing
Buckling Analysis
Thermal
Effects for Buckling Studies