How to determine strength of potted inserts
How to determine strength of potted inserts
(OP)
I have a problem where I am trying to fasten a class divider curtain on a Boeing aircraft to the top of the overhead bins and extending across the aisle. I am proposing to use aluminum U-channels that will be fastened to the top of the overhead bins using potted inserts (p/n SL3378-3-500) and screws (BACS12FA3K5) to attach the channels to the overhead bin.
What structural analysis do I need to do and how do I estimate the strength. My guess is the determining load wouuld be an in-service load but you would need to determine all other loads.
Can anyone help a first timer with this problem?
What structural analysis do I need to do and how do I estimate the strength. My guess is the determining load wouuld be an in-service load but you would need to determine all other loads.
Can anyone help a first timer with this problem?





RE: How to determine strength of potted inserts
"... and how do I estimate the strength" ... easiest way is to make a sample (of one insert) and test (out-of-plane and in-plane) ... out of plane is probably more critical in this application.
RE: How to determine strength of potted inserts
does Surlock give allowables for the inserts. We usually call out the generic NAS p/n for inserts, so I'm not sure which insert "SL3378-3-500" is.
Our designs generally assume a max load of 300 lbs per insert per 1in panel, probablly slightly more than 1/2 for .5in panel.
Wes C.
RE: How to determine strength of potted inserts
It depends tremendously on potting material, face sheet material and thicknesses, as well as core materials and density.
On top of that, allowables tend to be VERY process-sensitive. Is the core being undercut around the insert? How far?
A one-off pull test does constitute an allowable, at least as far as the FAA is concerned.
Having said all that, I agree with the statement that there isn't a whole lot of load on a curtain rod, as long as you slot one end longitudinally so as not to pick up any induced loads from airplane deflections. Make sure too, that the line-of-action of your load isn't too eccentric, which will cause the channel to try to pry your inserts out. Remember, short couples result in large forces.
If you can get your insert load down to less than 50 lbs. per insert or so, you should be able to substantiate the installation "by observation", as long as your company has a qualified process in place for insert installation.
Hope that helps.
SuperStress
RE: How to determine strength of potted inserts
RE: How to determine strength of potted inserts
PSS-03-1202 Insert Design Book, Issue 1, June 1987
I used the methods in this book in the past and got great results when compared to experiment (within 5% in all cases)
There are a couple of places you can order the book from, just search in Google in and you will find them.
RE: How to determine strength of potted inserts
If you need the exact details on materials (panel core and plies) contact me directly.
RE: How to determine strength of potted inserts