Beam Moment splices

[sam3990]

Hi all
I need some help in design of beam bolted connections. The SHS is 400x16, splice plates are 750x750x40mm thick and bolts M36. Lets say a moment of 100 kNm applies. By simple calculations
1) if i apply the revit theory, My/Σy2, i get a maximum bolt force of 31.91 kN. The net moment of inertia is only due to the bolts considering neutral axis at centre of the bolt group (which is 750/2=375mm)
2) If i apply beam theory, considering 40thk plates to be rigid enough, considering neutral axis at a depth d, so the net moment of inertia of the entire system is calculated using compression bearing area of the plates above neutral axis plus moment of inertia of tension bolts below neutral axis.
Using this I'm getting neutral axis = ~100mm and maximum bolt force 23.5kN.

Which one can be considered a logical method in the given scenario? Attached an image to give a summary.

I tried to validate using RAM connections but it lacks the capability to check splice as such. Can someone recommend a good way to validate these results?
I have scoured the net for Australian Tubular design guide 24 but havent found anywhere. Can someone please share if you have. Many thanks in advance. Cheers.

 

[centondollar]

The principle of the linear method relies on infinite stiffness of the plate, which is achievable in a shear tab type connection (in-plane stiffness of a plate is great), but not necessarily in a moment connection where the plates act in bending.

For the bolts, you could assume a forced center of rotation at the compression bearing point (upper or lower flange centroid) and calculate the bolt forces assuming a plastic stress distribution - the method can be found in any textbook on connection design. You will also need to check bolt prying forces, failure of the plate (yield line method), yielding/buckling/crushing of the RHS flanges and webs, and to make sure that the governing failure mode is plate yielding, not bolt rupture.

 

[icebloom]

Don't suppose you have access to Limcon (RAM connection predecessor, essentially the same thing but old school interface)? It has similar connection for hollow section, and so I would've thought RAM connection also has it (we've actually got RAM connection but I've never made the switch because Limcon is just so easy to use). In terms of software there is always Idea Statica too but I suspect you might not have access to it if you are looking for written resources.