Confusing Results in 2 End Rotations!

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aminamini
Posts: 24
Joined: Thu Jun 06, 2013 10:14 am
Location: SUT

Confusing Results in 2 End Rotations!

Post by aminamini »

Hi

I've modeled a 2-D steel moment frame and analyzed it using pushover method. forceBeamColumn element has been implemented in the analyses.
my problem is some confusing results. for example, in the last step of analysis the results for basicDeformation and plasticDeformation recorders for a specific beam are:
basicDeformation: 0 -0.00640318 -0.00642404
plasticDeformation: -1.1287e-019 3.90313e-018 -0.00243365

as can be observed, the total rotations (basicDeformation) of nodes i and j are approximately equal. however, the plastic rotation of node i is zero (3.90313e-018), unlike node j that the plastic rotation is -0.00243365.
I know that the total rotation includes some elastic and some plastic components and the elastic component limit for 2 end rotations of an element are same. so, why the plastic component of 2 end rotations are so different ?
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