Effective length of a column depends mainly on:
Analysis & Theory
Effective length is a function of end restraints (fixity or freedom) which determine buckling behavior.
What is the effective length of a column with both ends pinned?
Analysis & Theory
For both ends hinged (pinned), effective length is equal to actual unsupported length, i.e., Leff = L.
For a column with both ends fixed, the effective length is:
Analysis & Theory
When both ends are fixed, the effective length is minimum: Leff = 0.5L, due to maximum rotational restraint.
What is the effective length for a column with one end fixed and the other end free?
Analysis & Theory
Such a column is highly unstable and has the maximum effective length, Leff = 2L (worst case for buckling).
A column with one end fixed and the other hinged has an effective length of:
Analysis & Theory
For one end fixed and the other hinged, IS 456:2000 suggests Leff ≈ 0.8L.
Effective length for both ends restrained against translation but free to rotate is:
Analysis & Theory
If ends are restrained from translation but free to rotate (hinged), then Leff = L.
Which condition gives the shortest effective length of a column?
C
One end fixed and other free
D
One end fixed and other hinged
Analysis & Theory
Both ends fixed provides the shortest effective length (Leff = 0.5L), making the column most stable.
As per IS 456:2000, effective length of a column in a sway frame is greater because:
B
There is lateral displacement
C
There are more supports
Analysis & Theory
In sway frames, lateral displacement increases the risk of buckling, increasing the effective length.
Which type of frame leads to higher column effective lengths?
Analysis & Theory
Unbraced (sway) frames allow lateral movement, increasing effective length.
What is the effective length of a column in a braced frame with both ends effectively held in position and direction?
Analysis & Theory
As per IS 456:2000 Table 28, for both ends held in position and direction (braced frame), Leff = 0.5L.