Jun 2, 2015 #1 addagalla Aerospace Oct 24, 2012 3 0 0 IN 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.
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.
Jun 2, 2015 #2 rb1957 Aerospace Apr 15, 2005 15,595 0 36 CA um, huth's equation is not AG/L ... (that'd be the difference) another day in paradise, or is paradise one day closer ? Upvote 0 Downvote
um, huth's equation is not AG/L ... (that'd be the difference) another day in paradise, or is paradise one day closer ?
Jun 3, 2015 #3 SWComposites Aerospace Nov 6, 2000 3,297 8 38 US Most of the joint flexibility is not fastener shear deformation. Have you read Huth's paper? Upvote 0 Downvote
Jun 3, 2015 Thread starter #4 addagalla Aerospace Oct 24, 2012 3 0 0 IN I have not read Huth's paper. But what I am doing wrong if i Use AG/L as CBUSH stiffness. Upvote 0 Downvote
Jun 3, 2015 #5 RPstress Aerospace Jun 4, 2003 846 0 0 GB You will be overestimating the stiffness and this should predict more load transferred on the first fastener. http://files.engineering.com/getfile.aspx?folder=c9483ab2-674a-4137-b36b-04704f132608&file=Huth,_Influence_of_Fastener_Flexibility_(stiffness)__on_the_Prediction_of_Load_Transfer_and_Fatigue_Life_for_Multiple-Row_Joints.pdf Upvote 0 Downvote
You will be overestimating the stiffness and this should predict more load transferred on the first fastener.
Jun 3, 2015 #6 SWComposites Aerospace Nov 6, 2000 3,297 8 38 US 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. Upvote 0 Downvote
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.