buckling strength control - modern principles

[trickstersson]

Hello everyone!

I have to verify a steel structure. I am using FE code Abaqus to calculate forces, moments and stresses. I know how to verify moment stress and normal stress (just calculate maximum stress in members which should not exceed yield strength divided by safety factor - I am using EUROCODE 3 as a guide). But I have some problems with buckling control. Here are my questions:

1. How should I do buckling control? Use standard (for example EUROCODE 3) and for every member calculate maximal allowable force and moment? It would take me too much time, I have to do it fast.
2. How is buckling control done these days? With sophisticated FE codes I believe there is faster methods than using standard's equations. I red somewhere that if I include local and global imperfections in the model, than I just have to verify moment stresses in members?
3. Which principle does software like TOWER use?. Does it takes standard equations, or does it use other method to do buckling control?
4. What is appropriate buckling length for a member welded on both ends? Buckling length should be 0.5*L, where L is the length of the member, right? Or should I take into account stiffness of the joints?

I would really appreciate any help, since I am new in this business.

Cheers!

 

[jayrod12]

If you have a bunch of columns/beams that are the same (size, length, etc) you could just run the hand calculations on that one to prove that the worst case works for each column/beam size. Then you don't have to check each one.

Just a thought. But I also do the majority of my design by hand still. Just starting to get into modelling.