Steel girder splice design/block shear failure modes 1

[engidude]

Hi, guys:
I'm new to Steel girder splice design. I don't have comercial software( such as the PENDOT software). I'm cranking my own mathcad sheet.
The bolted splice has 4 rolls( roll center line across flange) of bolts x 6 bolts each roll. I'm running into diffilcty to check block shear since it has too many potential failure modes, I figure that I have to either exaust all failure modes in my check or figure out which mode controls( which means excluding failure modes that don't control obviously by looking at equation LRFD 6.13.4-1).The problem is that (to me) there are too many block shear failure modes because of the complex bolt patterns used.

the examples I can find online( such as the FHWA example) had bolt pattrens too simple, thus not as many failure modes mentioned.

I have attahced some failure mode sketches I have on mind now( definitely these are not all potential ones),
Could you give me any ideas?

 

[nutte]

I'm reminded of my college steel professor: "First make sure the block shear path you're checking can actually happen." Most of your potential failure modes can't occur. The girder flange will still be connected to bolts in the plate. If the girder flange is still in one piece, the other bolts will still be engaged, and the plate won't be able to separate along the lines you've drawn.

There are two modes to check: 2-1, and one not shown, a mode like 1-5, but with two lines drawn, one each side of the plate. 1-1 could happen, but it won't control over straight net tension failure through the bolt holes, if the proportions you show are close to actuality.

 

[engidude]

Thank you Nutte.
Good point!

 

[engidude]

Nutte:
As I understand, failure mode will possibly ocuur if the tearing line circles through bolt center points and leaving no bolts still in place to connect the plate under study to other plates.

Please look at the attached failure modes for flange plate, outer splice plate and inner splice plate, did I miss any potential modes?

Thank you.

 

[slickdeals]

See attached, which was part of the documentation in AISI Splice (Dr. Firas Ibrahim)

 

[engidude]

slickdeals,thank you very much.
that's very helpful.