Steel column connection

[Anonymous]

Hello,

I'm designing the connection for steel column baseplate. My column is defined as moment release, so when I'm selecting the steel column to design the connection, ROBOT atomatically defines the connection is 'Fixed Column Base Connection'. So, the problem is I want to change the connection to 'Pinned Column Base'. Is there any way(s) to change the type or automatically define by ROBOT itself?

Thanks.

[Artur.Kosakowski]

No, this is based on the support type but if you defined release at the bottom of a column with fixed support the forces imported to the connection module be with 'zero' bending.

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[Anonymous]

ok, then the column is still will be analyze as Fixed column base even the bending is zero?

[Artur.Kosakowski]

Correct unless you change the support type from fixed to pinned.

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

[Anonymous]

but I still not clear enough, my support is pinned, my column is released as pinned at the end, but why the connection is still defined as fixed column base?

[Artur.Kosakowski]

Then it would have instability reported till the moment you decide on either of them. Attach the rtd file and indicate the column number.

[Anonymous]

yeah, there is a lot instability reported n actuall i thaught it is normal .

please take a look at my attached file, and the column number is 77 at the portal frame.

https://www.dropbox.com/s/iemehn302okem1r/20130311a-tuas%20south%20%208%20%28LATEST%29.rtd

[Artur.Kosakowski · Accepted solution]

Personally I would delete the short RC bar under the steel column 77 and then I would extend the column 77 e.g. 20 cm downwards. In such created node I would define a pinned support to create the pinned column base connection. Finally I would use take care about the pier in the RC Spread Footings module of Robot.

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

[Anonymous]

Thanks a lot for your time. 😃

[Anonymous]

1 more I need to ask, If i create new connection, then how do I assign them to the existing structure?

[Artur.Kosakowski]

You should select part of the structure (e.g. column and its supported bottom node) and then create a connection. You cannot 'assign' connections created manually to the model.