NAS6605-12 Bolts Bending Stress 1

[Kakalip]

Hello,
I wanted to check what would be bending stress allowable for NAS6605-12 bolts which has only 160 Ksi as Ftu and 95Ksi as Fsu.
Please advise if anyone has idea of dealing with same.

 

[bf109g]

Hi Kakalip -

I've never seen an allowable for bolt bending stress. If bending was an issue I just did something like as shown in Bruhn D1.14. I think there's something in Flabel as well.

 

[SWComposites]

How is the bolt loaded? single shear? double shear? what are the strap material?

How are you calculating the bending moment in the fastener? Are you accounting for the moment reaction by the head/nut?
Where along the bolt is the critical moment?

Why can you not use the Ftu allowable against the peak stress? Are you trying to account for plastic bending?

 

[JJ22mW]

Depending on what the bolt is used for you may need to check for yielding under limit loads in addition to an ultimate loads analysis. You would of course using be using Fty as your bending stress allowable.

 

[audacious12345]

Calculate bending moment use Ftu to get your allowable load if its not sufficient use plastic bending if this is not sufficient either then do some engineering test on bolt. But engineering test will give you only one data point not good enough for certification. Try Bruhn D1.14 for bolt bending strength and Bruhn C3.14 for plastic bending.