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Effective Length situation 1

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BST-98

Structural
Mar 5, 2024
11
Good day, All

My query is regarding this situation between steel beams supported at either ends with a column in the middle being braced along its weak axis.

If the beam can take 2% of the axial load applied on the column, does this mean that the column is therefore braced in it's strong axis and therefore the effective length for the strong axis is the same as the weak axis and design the axial load for a shorter length column than the full length?

For further context, the beam column connection is designed so that the flanges of the column are prevented from buckling.
To my understanding the answer above is yes, but I'm hearing mixed discussions and would like to clarify

Image below is for reference, excuse the stick diagram.

Effective_lengths_query_gihxnx.png
 
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Thank you everyone for your valuable input, I appreciate the attachment of relevant literature very much.
 
A good presentation linked there BAretired. It has a good summary. And steps the first principles out in detail pretty clearly.

(And for the many who are still following along, I hope there were some snippets of good information had from it. IMO the tone of this thread descended somewhat probably mostly due to me. I sometimes get passionate and righteous. Buckling of steel members has been a particularly strong interest of mine. From beams to pressure vessels under vacuum... It fascinating and complex very quickly.)

BST-98 said:
Thank you everyone for your valuable input, I appreciate the attachment of relevant literature very much.
Go forth and use it wisely. What you are proposing is perfectly workable, though do be careful. I'd be proceed using buckling analysis and see you ~3x assuming the ends of the horizontal beams are pinned. That is quite a conservative approach but you might find what you have already specified already meets that criteria.
 
Are the beams restrained against horizontal movement by some means of shear walls, bracing, etc.?

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik
 
Here is an example from CISC outlining force and stiffness requirements:

Screenshot_2024-04-16_093950_pwyncl.png

Screenshot_2024-04-16_094003_x4k9ky.png
 
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