Releasing moment for beams

[perfectaccess]

Hi community

I have moment frame resisting system,and I have couple of beam fail in shear under seismic combination ,so release the moment for that beam and it is still fail under same seismic combination,

So if it is not acting as frame ,why it fail under Semitic,

is there any interpretation please?

I used Etabs,but id doesn't matter the program,I am asking about the concept.

Thanks

 

[DaveAtkins]

Is it also failing in shear due to gravity loads, without seismic?

DaveAtkins

 

[perfectaccess]

no I checked the gravity combination it is okey,that why I suspect this!!!!

 

[haynewp]

Is there vertical seismic in the combination?

 

[KootK]

Is the beam designated as a moment frame beam within the software and therefore possibly being capacity designed in shear based on the available moment capacity of the beam rather than the applied moment force?

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[Agent666]

Sounds like you are relying wholly on a computer program to work out your design.

Aside from this, what do your hand checks of the member tell you, does it still fail under the seismic case gravity load as a simply supported member, or do you get a different capacity?

 

[perfectaccess]

Dear All,

The load combination which is cover
=1.2D+0.5 L+ Spectxy+Ev
And it is ordinary moment resisting frame ,so shear is not calculated based on capacity

I heard one comment in the work I didn't Understand ,and it may give interpretation to the problem,
I have been told if you want to make the beam not acting as moment resisting frame in the model you have not to release the moment in the beams(as I did), you have to release the shear in the column at the point interests with column?

Can anybody interpret why I do this?and even if this right or wrong?

 

[perfectaccess]

any further comments guys

 

[KootK]

Can you post a screen capture of one of your beam column joints showing the releases?

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[perfectaccess]

Hi Kootk

I upload video which is much better than picture.
combination 8-6 contain spect according to UBC97
THE problem that I release the moment,and I still have some moment and shear at the beam corner.

if anything nit clear pls let me know.