Moment Release and Steel Connections

[Anonymous]

Hello,
I have been doing analysis of a steel structure with truss in Etabs.

Do i have to release moments in the truss??
i am designing purlins as to be welded , do i have to release moment??

[acbsdesign]

Depending on the lateral loads.

You have to make sure the building will resist wind and earthquake if applicable.

[Anonymous]

Thank you sir,
But my question is, do the purlin members resist moment? ( how should they be designed)
should i assign hinge joint to the purlin joints?
should i release moment from the diagonal and vertical member in the truss since they take only axial loads!

[acbsdesign · Accepted solution]

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@Anonymous wrote:

Thank you sir,
But my question is, do the purlin members resist moment? ( how should they be designed)
should i assign hinge joint to the purlin joints?
should i release moment from the diagonal and vertical member in the truss since they take only axial loads!

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1. Purlin members do not need to resist moment from what can be seen from the picture

2. Yes, you can assign hinge connection to the purlin joints

3. Yes, but this has to be investigated

[Anonymous]

Thank you sir, for your valuable time and knowledge.
it means a lot.

[hachnayen]

Yes to me pratically it should not e hinged. Purline must be end released as those member is just work like collector . but the truss is practically not like theoritical which describes  that truss provide only resistance to axial force. in case of 3d truss this should not be case. experienced engineers can reply far better.