Hi Guys,
I came across this equation and a writeup for these two methods:
1) hole tension / and hole bearing / bending to determine the stress intensity for essentially a flat plate. However I am not sure where all of the values come from.
I am not sure where the 61.23lbs and the 386.09lbs...
Thanks Will.
I did come across a few specs.
Do you mind pointing me to where I can find these FAA 'AD's"??
As for the thickness it measured at 0.042" remaining thickness (Im sure primer scratched off) but none the less yes it was under the material spec which should be (0.050" thk remaining...
Thanks for that Will.
I noticed that the OE drawing indicates that the chem-mill pocket is 0.050" however it measures around 0.042"thk.
When you do such a repair analysis would you consider the strength of the chem-milled pocket area for equivalent strength?
Or how else would you approach it?
thx rb.
I have 'no data' to the original strength. just the material data that I provided above. i.e. 0.1" thk chem milled to 0.040" pockets. Repair extends from 0.1" edge into Pocket area of 0.040" thk.
I would agree and use 'equivalent strength' for calculations. However what would you use...
Thx WK.
I believe the chem milled pockets are actually thinner (0.040 to 0.050) however I am not 100% sure.
I am just curious as to the analysis approach. However saying that for a 0.063" thk doubler - if reduced head csks where used - NAS1097E?
Again I am merely intrigued by the repair...
Im assuming that the chem milled pocket thickness is 0.063"...
And yes agreed. dblr ok. and should be close or same as the pocket thkness.
And also agreed I assume the filler does nothing a structural filler.
I am wondering how would you write the stress to support 25.571?
As would your...
good questions. see below.
Pressurized, unpressurized or fuel-wet one-side, etc? - Pressurized - cargo door (external)
What was the purpose of the added doubler? material-removal beef-up? patch-over a hole? etc. material removal beef up (removed minor damage)
Why the added 0.100 thick...
Hello,
I saw an interesting topic the other day - in which an external aircraft repair was done using a thinner gauge repair doubler.
The basics are:
- 0.100" thk original chem milled skin
- 0.100" filler
- 0.063" thk external repair doubler
- the reason is that a thicker doubler would...
Agreed. I will likely go through with testing this for my own curiosity - setting up the test to properly demonstrate this is another ordeal.
However my original question with this is and still is 'What is best conservative approximation and calculation that can be made in this sense?'
I have...
probably a good description of it...
what do you mean by 'That'd be Fsu'??
I was assuming using the Fsu value from MMPDS 3.5.10 would be a Conservative approach for the calculation?
Doing some more reading on pull out strengths how does this sound:
Pov = Pull over strength = which is the force required to pull the sheet over the head of the screw / washer.
t1 = thickness of sheet metal = 0.032 in
Dws = screw head / washer head diameter = 0.438in
Dh = hole diameter =...
I was hoping it would be a bit simpler than that to be honest. I have also used the Bruhn rivet tension allowables as a comparison i.e.:
Table A Bruhn D1.28 indicates a 3/16inch rivet Ultimate Tensile is 354 lbs. And the applied load per fastener is roughly 50lbs so therefore:
Even with using...
Thanks for pointing that out.
wrt to (Fsu*pi*Dh*t) what exactly is 'Dh'? the Diameter of the head I assume? whether it be washer head or rivet head? and What value of Fsu would you be referring to that would be unconservative?
As for the rest - absolutely agreed! A test would provide the real...
Additionally the size of the rivet is much smaller than the surface area of the washer head or actual fastener that would actually be used so to say that the Rivet Allowable used in the closest gauge and diameter @ 0.032" thk and 3/16" diam. with allowable of 354 lbs - is actually an value which...
Sorry - Yes of course I could get a piece of 5052 and do a simple pull test.
I would also just like to complete the analysis as I am determined to prove it on paper now... And yes just an operator builder and there is no concern for the case just curiosity to prove this analytically... As it...
hey - thanks for the reply.
Yes I agree the reason for using the 5052 for calcs is because the actual material is unknown other than it is Aluminum by inspection and 0.032" the calculations I have done only to meet an absolute worst case scenario and prove the method to pass by analysis.
As...
Hey Guys,
I am trying to simplify a Calculation to get a Margin of Safety Calculation for an Aluminum sheet metal pull 'Thru' Calc to ensure enough fasteners are being used and the sheet metal is thick enough etc... I am taking a shot at this here so any suggestions would be greatly...
