Compression buckling of column

[dccd]

Homework Statement

For the minor axis , the buckling length shall be 2*5 = 10m , right ?? (because in minor axis, it's cantilever , nothing to restrain the column on top) . However, the program detect the buckling length as 5.0m.

Relevant Equations

Not applicable

Hi, all. The top beam is subjected to uniformly distributed load. FYI, the column is 5m in length. As you can see, the major axis of column is connected to the beam with moment connection on top. However, in the minor axis of column, there's nothing to connecting them.For the major axis, the buckling length shall be 0.7*5 = 3.5m (K = 0.7 for bottom pinned, top fixed condition) ,For the minor axis , the buckling length shall be 2*5 = 10m , right ?? (because in minor axis, it's cantilever , nothing to restrain the column on top) . However, the program detect the buckling length as 5.0m.So, my question, for the minor axis, is it considered as cantilever ? Or since in the major axis, it's already gt the moment connection, in minor axis of connection, there's really doesn't matter whether the minor axis of column in restrained or not...

 

[KataKoniK]

Hi there,

Thank you for bringing up this question. I can provide some insight into the buckling length for the minor axis of the column in this scenario.

Firstly, it is important to note that the buckling length is the distance at which a column will buckle under a certain load. It is a critical factor in determining the stability of a structure.

In the case of the minor axis of the column, it is correct that the buckling length would be considered as 10m, as it is a cantilever with no restraint on top. This means that the column is free to rotate and will experience a higher bending moment, resulting in a longer buckling length.

However, the moment connection on the top of the column in the major axis does play a role in the stability of the structure. It provides additional support and stiffness to the column, which can reduce the buckling length. This is why the program may detect the buckling length as 5.0m, as it takes into account the moment connection on the top.

In conclusion, for the minor axis, it is considered as a cantilever with a buckling length of 10m. The moment connection on the top of the column may play a role in reducing the buckling length, but it is still important to consider the full length of the column for stability analysis.

I hope this helps to clarify your question. Let me know if you have any further doubts or concerns.