plastic hinges in columns

04-Unexpected behaviour/errors
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Joined: 25 Dec 2018, 22:56

plastic hinges in columns

Post by yahia » 25 Dec 2018, 23:11

Hi everyone , i modeled 3d RC-frame using pushover analysis, after getting results and curve is plotted ,i check chord rotation for plastic hinges .
the plastic hinges is appeared in beams and ground columns , and didn't appeared in upper stories.
what is the reason for this phenomenon ?
the attached file clear my point ... 0.spf?dl=0

i hope i get answer soon
my best regards

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Joined: 22 Jul 2011, 10:19
Location: Cookeville, Tennessee, USA

Re: plastic hinges in columns

Post by huffte » 26 Dec 2018, 15:23

This is the typically preferred mechanism for design in modern buildings. The so-called strong-column, weak-beam concept in which hinges form in the beams of each floor and, finally, in the ground floor columns to complete the mechanism. So perhaps you are modeling a properly designed building? Only you and you supervisor can say for certain.
Tim Huff

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Joined: 25 Dec 2018, 22:56

Re: plastic hinges in columns

Post by yahia » 26 Dec 2018, 18:54

Dear huff
Thank you for responding ,what i meant ,the plastic hinges formed in all stories (beams and columns) when I choose chord rotaion in yielding(automatic calculation) .But when i started to specify a value for chord rotation to determine the preformance level for plastic hinges ,it started to take another stage (change its colors),except the upper columns
For example
Chord rotation in operation stage=0.005
Chord rotation in lifr safety stage=0.01
Chord rotation in collapse prevention stage=0.02
The previous attached file cleared that point
My best regards

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Joined: 06 Jul 2007, 04:55

Re: plastic hinges in columns

Post by seismosoft » 30 Dec 2018, 11:30

The change of color means that a new performance criterion has been achieved, i.e. a performance criterion with a higher chord rotation value.
Seismosoft Support

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