This method of assessment involves reading coefficients from graphical data for use in subsequent equations. The spreadsheet automates all the curve reading to determine the proof and ultimate strength of lugs in an expedient manner. The spreadsheet has been produced by Abbott Aerospace an independent consultancy company offering structural engineering services the aerospace industry. You can contact them by email This email address is being protected from spambots. You need JavaScript enabled to view it.
Calculation Reference
Bruhn - Analysis & Design of Flight Vehicle Structures
Currey - Aircraft Landing Gear Design
03 Oct 2008
Last Modified
03 Oct 2008
File Size:
1,895.00 Kb
File Version:
File Author:
Richard Abbott

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Comments: 4
abbottaerospace 15 years ago
The fatigue reference on sheet 3 is just a word of warning to keep an eye on pin diameter vs lug thickness. I know that in aerospace applications many companies insist on a minimum static strength lug margin of 25% against ultimate loads to cover themselves against potential fatigue issues.
i.e. single shear bad, double shear good. Thin lugs good, thick lugs bad
I have done lug fatigue analysis but it is usually to a proprietary company fatigue method....
abbottaerospace 15 years ago
The 'curves' sheet is included so that digitization of the reference data can be validated if required. I can't recall that there are any links to it from the calc. sheet, but I would need to check to be sure.......
The stress concentration issue....good point. I will try and post another reply tonight when I have looked into this further
abbottaerospace 15 years ago
This is a great calculation and I will find it very useful.
There is mention of "Repeated Loads" on sheet 3 which gives some guidance on fatigue but it is not developed. It recommends the use of a suitable SN curve and an appropriate stress concentration factor. I have encoded a spreadsheet to calculate the lug stress concentration factor using Peterson's. Do you think it is appropriate to use both methods together?
Also there is a worksheet entitled 'Curves' but I don't think it forms part of any calculation. Can this sheet be deleted?
Thanks again you for your effort.
JohnDoyle[Admin] 15 years ago
This is a wonderful spreadsheet. All steel designers should take a copy. Thank you AbbottAerospace