Connection Analysis - Fastener Loads on Fasteners of Different Sizes

[rmmoraes]

Hello,

In a bolt group one of the bolts are oversized. How do you calculate the new bolt load?
I heard discussions about it and anyone came with a conclusion.
Some choose to go with Huth approach, some goes to (D2 / D1) and some with (D2 / D1)^2 approach.
Which one do you agree is the best approach?

Note: The last discussion I had about this subject the following conclusion came:
1 - Huth only for splices;
2 - D2/D1 only for bearing critical joints;
3 - (D2/D1)^2 for shear critical joints.

But and for mixed joints where you have for one structure a shear critical joint and for the other structure a bearing critical one?

Could you give me a light on this. I couldn't fined any book or paper talking about it... except Flabel.

 

[DrZoidberWoop]

The best practical approach is likely going to be the one that allows for the most simplification. If you're looking for a purely technical answer, a simple spring model or FE analysis would probably suffice. Depending on your industry, you may have enough flexibility to either 1) neglect the larger bolt size, 2)replace it with a smaller diameter bolt if the connection is slip-critical, or 3) give up and just weld the darn thing (lol).

 

[TLHS]

What are you doing and how accurate do you need to be? Also, what are the hole clearances (i.e. does the larger bolt have the same clearance to edge of hole as the smaller ones?

Why do you have one fastener that's a different size?