Calculating Bolted Joint Stiffness

[addagalla]

we are modelling some bolted joints using CBUSH elements in FEM. can anybody help what is the difference in using huth method and using AG/L to calculate shear stiffness. Thanks in Advance.

 

[rb1957]

um, huth's equation is not AG/L ... (that'd be the difference)

another day in paradise, or is paradise one day closer ?

 

[SWComposites]

Most of the joint flexibility is not fastener shear deformation. Have you read Huth's paper?

 

[addagalla]

I have not read Huth's paper. But what I am doing wrong if i Use AG/L as CBUSH stiffness.

 

[RPstress]

You will be overestimating the stiffness and this should predict more load transferred on the first fastener.

 

[SWComposites]

Agreed. Way too stiff by only considering fastener shear deformation.

Best approach - fab a two row joint specimen, test it, measure displacement. Then correlate your FEM approach to the test.