Beam-to-Beam bolted connection 5

• Jan 10, 2021

• #2

MIStructE_IRE

Structural

Sep 23, 2018

816

IE

You note “assuming bolted connection can transfer moment”. This detail looks reasonable as a pinned connection to transfer shear - not moment. Is this supposed to be a fixed end??

 

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• Jan 10, 2021

1
• #3

kostast88

Structural

Jul 22, 2013

112

GR

There is no moment transfer, this is a typical shear connection.

- No loads on transverse beam, except loads from connection and end reactions

Silly, but If there is no load on the beam, where is the end reaction coming from? You probably mean self weight only?

I am not convinced the plate on the back is doing anything, other than subject the bolts to double shear. But if you have no loads or small loads as said above, that wouldn't be a problem, why add it?

I have no data of what you are trying to do so don't take my word for it. You know your system.

If you are not a structural engineer then hire a competent engineer to do the design for you. Free advice on forums and "Googling" is by no means substitute for consulting services which cost time and money.

 

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• Jan 10, 2021

2
• #4

MIStructE_IRE

Structural

Sep 23, 2018

816

IE

I’m not convinced that arrangement even gives you double shear in the bolts. The back plate is redundant really.

 

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• Jan 10, 2021

1
• #5

MegaStructures

Structural

Sep 26, 2019

376

US

If the connection needs to carry moment (cantilevered?) you need to connect the flanges. For the flange connections you can specify a full depth groove weld without explicitly checking the strength of the weld if the filler metal is stronger than the base metal.

I assume this doesn’t need to be a moment connection though. Are the beams connected at both ends? If so a simple shear connection will do. Look up double angle connections. The plate at the back isn’t needed.

You need to have a competent structural engineer design the beam and connection. It’s likely you have loads in the beam that you aren’t even aware of unless they are interior and decorative only.

I’m not sure where you are located, but in my area you couldn’t get this approved by the building department without a PE stamp anyway.

“Any idiot can build a bridge that stands, but it takes an engineer to build a bridge that barely stands.”

 

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• Jan 10, 2021

• Thread starter
• #6

SiggiN

Marine/Ocean

Mar 18, 2019

33

NO

Thank you guys!

I will have someone experienced take a look at this, but I did study structural engineering a long time ago (in a galaxy far far away) so thought it a nice mental exercise (haven't worked as a structural engineering...yet)

Sorry! I could have supplied more information:

- I'm located in norway (Eurocode 3)

- HEB140 to carry weight of floor (2kN/m^2 * load factor), see picture below

- Maybe i'm overly conservative when assuming moment connection?!
- My reason was to ensure proper bolt size and grade (pending calculation). With the moment acting as a couple
- Calculating bolts based only on shear seemed...too simple

 

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• Jan 10, 2021

• #7

human909

Structural

Mar 19, 2018

2,243

AU

SiggiN said:

- Maybe i'm overly conservative when assuming moment connection?!
- My reason was to ensure proper bolt size and grade (pending calculation). With the moment acting as a couple
- Calculating bolts based only on shear seemed...too simple

Click to expand...

There is some moment induced in the connection due to eccentricity, this may be what you are referring to.

The connection itself is quite 'flexible' and would allows some rotation hence it is typically treated as a simple pinned connection with no moment transfer from the supported beam.

 

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• Jan 10, 2021

• #8

engineering_patrol

Structural

Aug 9, 2020

62

GR

this is a pinned connections of course. It is a "double cleat connection".

 

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• Jan 10, 2021

• #9

r13

Civil/Environmental

Oct 26, 2019

5,988

US

Almost every structural joint will have some moment capacity, but it is usually ignored in the analysis, as the not very meaningful moment can be relieved through the flexibility of the simple shear connection, if the entire structure is stable.

 

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• Jan 12, 2021

1
• #10

12345abc6ttyui67

Structural

Jan 8, 2018

197

GB

As noted above, this is a very standard double cleat connection. Assume pinned ends / no moment at the connection to the supporting beam.

Typically I would assume the 2 bolts between the double cleat and incoming member are subject to a bending moment (due to the end reaction x offset from CL of the supporting beam to bolt CL) and shear (due to the end reaction), and act, if you like, as a continuation of the incoming beam. These will be in double shear for a double cleat.

The 4 bolts between the double cleat and supporting member are subject to single shear (due to the end reaction).

The backing plate does not allow for double shear in the bolts (it's loose usually) and is usually provided to stiffen the supporting beam's web if bolt tension (due to any axial load in the incoming beam for instance) is causing web bending. In some instances the backing plate may be welded to the supporting beam in order to improve bearing length for the bolts, but I don't see that often.

 

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• Jan 12, 2021

• Thread starter
• #11

SiggiN

Marine/Ocean

Mar 18, 2019

33

NO

Thank you to all!!

 

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