stiffener vs. "connection plate"

[HgTX]

There are designers who believe that a connection plate (which looks just like a transverse web stiffener except that a diaphragm or crossframe attaches to it, and thus has positive connection to both flanges whereas a stiffener might not) doesn't count as a stiffener, and thus is not to be taken into account when calculating required stiffener spacing and panel width and adding intermediate stiffeners.

I can't find this written anywhere, but I've heard it stated multiple times.

Does anyone know where this comes from?

Hg

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[bridgebuster]

AASHTO LRFD 6.10.11.1.1 permits a stiffener to also serve as a connection plate.

 

[HgTX]

Anyone know where the perception to the contrary comes from? That will help in battling the misperception.

Hg

Eng-Tips policies: faq731-376

 

[graybeach]

I haven't experienced the perception that a connection plate can't be a stiffener. Could it be that someone has the fact that stiffeners shouldn't be used at connection plates (unless they are connected to the flanges) backwards?

I have seen recent designs where bearing stiffeners are used as connection plates for the end diaphragms but are not positively connected to the bottom flange. Instead they are just milled to bear. Not a good seismic detail.

 

[HgTX]

Dunno, but I've heard it in multiple quarters, and so have others--just recently I heard from a fabricator that a DOT was not letting them use the connection plates to define panel widths for web out-of-flatness.

And I've seen some *really* tight stiffener spacing, connection plates alternating with "real" stiffeners, that strongly suggests that someone wasn't counting the connection plates.

Hg

Eng-Tips policies: faq731-376

 

[Qshake]

I've not heard that either and have for years used the plates for dual purposes.

Perhaps there were details long ago for a specific DOT that defined each plates role as a stiffener or connection plate that made them mutually exclusive.

Regards,
Qshake

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