post tension equivalent frame
post tension equivalent frame
(OP)
Would like to use generic stiffness analysis computer software to analize a post-tensioned beam - column frame for lateral loads. To include the post-tensioning as a load case for column and foundation design, are the secondary moments added as concentrated moments at the beam column joints or perhaps the unbalanced post-tension uniform load added to the beams?





RE: post tension equivalent frame
The secondary prestress moments are the result of Secondary Prestress Reactions.
Use the reactions.
RE: post tension equivalent frame
RE: post tension equivalent frame
RE: post tension equivalent frame
Yes, they are normally pretty small compared to the applied vertical load effects but not always depending on the prestress arrangement. I think most people ignore them unless they are significant.
RE: post tension equivalent frame
I've designed several different types of PT structures and I did pay some attention to the secondary reactions. I never see any significant seacondary reactions in comparsion with the reactions from graviy or lateral forces. I wondering when these secondary reactions could be significant. We ceryainly need to take the significant reactions into consideration. Do you realize any situations that require your attention?
Thanks!
RE: post tension equivalent frame
It depends how close your tendon profile is to a concordant profile. For a concordant profile the secondary reactions are zero. The more removed the profiel is from concordant the larger the secondary reactions.