Eurocode 3 Shear Verification

[arminiusii]

Good Morning at all

I have a question regarding to a design verification.

I have a connection that is composed by four M20 bolts, located at the extremity of an ideal square. As per Eurocode 3 this connection could be classified as Shear Connection - Category A Bearing Type.
Moreover because the bolt is M20 the difference between the bolt diameter and the hole diameter should be 2mm.

My concern is relative to :
1) the tightening torque to apply in order to assure the correct assembly, because anyway the Catergory A (shear connection) should respect the EN 15048-1:2007 (Non-preloaded structural bolting assemblies). Can I apply something 400Nm of torque?
2) How I have to consider the Sheat Load on the junction? To verify the bolt can I simply divide by four the total shear load acting on the junction? It is possible that the 2 mm of difference between the diametere of the hole and the bolt could bring to a non loaded bolt? Becuase some do not have contact to the plate. How many bolt I have to consider for the design? In the normative (UNI, Eurocode 3, etc...) where I can find this scenario?

Thanks for you answer

 

[Agent666]

Usually all bolts are taken sharing the load evenly. It's assumed at the ultimate limit state that there will be sufficient deformation to achieve this even if there is some minor misalignment or out of tolerance for the 2mm oversizing.

While bolts are not tensioned they are still torqued to a condition that would bring the assemblies into contact.

Not familiar with Eurocode, but the above is true of most codes for non tensioned bolts.

 

[klaus.]

Yes true for Eurocode....divide the force by the 4 bolts...


best regards
Klaus