AISC 13th edition Design Example H5-c (CD-room)

[warrywall]

Design Example H5-c in AISC 13th edition CD-room intends to illustrtae the correct interpretation of section H3 (page 16.1-74) of the code. In this example they calculate the Unity Check using equation H3-6 considering like if the maximum moment and shears occur exactly at the same location but we all know that this is not the case for a simple supported beam. Does anyone know why they did this?
Regards
David Guerrero

 

[ishvaaag]

Maybe they choose it as a worst case, like in a cantilever.

 

[jdonville]

warrywall,

AISC is very responsive to all inquiries (you may not be entirely satisfied with their answers, but they do respond). Suggest that you email the technical solutions center and ask them directly.

http://www.aisc.org

Jeff

 

[warrywall]

I did already and they (AISC people) basically responded that they do understand that maximum bending and shears do not occur at the same location but they combined together them just because it is conservative. In my opinion I don't think that is a good answer.

 

[JoshPlumSE]

I think when folks are putting together example calculations there is a real give and take between showing a quick and simple solution and showing one that is most accurate.

I prefer the solutions that show the quick and simple calculation. But, I also like it when they have a side note that talks about the simplification they used and why it is justfied in this situation.

But, not all examples are all that well spelled out.... In fact, I find that relatively few are.

 

[jdonville]

warrywall,

The folks at AISC seem to have decided to simplify their example in the name of 1) simplicity and 2) conservatism. That is their perogative, and a defensible position from a liability standpoint.

You, as an engineering professional, may decide that you want to be a bit more rigorous about simultaneous combined loadings. Note, however that your shear and moment may not be distributed entirely as your model predicts. Exercising judgement is your perogative.

Jeff

 

[warrywall]

To be conservative they could have added a safety factor and that's it and not show a wrong procedure.