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RE: Bent Beam/Frame

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Sorry, I will withdraw my statement below.  A rigid frame that has pinned supports "will" develop lateral reactions due to vertical loads applied to the frame.  However, in this case if the base is free to move laterally, the horizontal reactions are not developed.
 
 
Bill Sherman
CH2M HILL / DEN
720-286-2792
 


From: William.Sherman(--nospam--at)CH2M.com [mailto:William.Sherman(--nospam--at)CH2M.com]
Sent: Friday, September 07, 2007 11:18 AM
To: seaint(--nospam--at)seaint.org
Subject: RE: Bent Beam/Frame

No, you cannot just ignore the horizontal reactions from the rigid frame.  Greater rigidity may reduce the force but it does not eliminate it.  You should analyze the horizontal reactions based on frame analysis for the stiffnesses provided, and follow the load path and design for it.
 
 
Bill Sherman
CH2M HILL / DEN
720-286-2792
 


From: erik gibbs [mailto:erik.gibbs(--nospam--at)gmail.com]
Sent: Friday, September 07, 2007 11:04 AM
To: seaint(--nospam--at)seaint.org
Subject: Bent Beam/Frame

We are providing a steel bent beam/frame in a custom home to support the ridge beam within the ceiling instead of the typical king post to ceiling beam. The Steel frame is sized to fit within the depth of the R.R. and it is a 3/12 pitch, made with 2 square steel sections and a full penetration weld connection is provided at the apex, where the 2 beams meet. The bearing of the frame is at a 4x post at each end, hidden within the wall. 
 
Now my question is, if you determine the reactions using a simple FBD there will be an x & y reaction at the bearing points at the 4x posts, but if the steel frame is designed as stiff as possible to limit the deflection to negligable amounts then I am assuming that there will only be vertical reactions in the y direction. Therefore a wood post can be used without designing the connection for a very large reaction in the horizontal direction. 
 
Am I right in this assumption?  
 
Erik Gibbs