Experimental plastic response during static loading 1

[Teodah]

Hi! I'm looking for a study where some metallic Component have been statically loaded, preferably to failure while strains have been measured. I'm not looking for a study of an ordinary test specimen but more of a complex geometry like T-joints or bathtub joints. I have looked and looked after a study like this and would be very thankful if someone has a tip.

 

[rb1957]

? OEMs do this all the time, but probably never publish. And rarely intentionally to failure (some do, to get that last data point; some don't, if it meets requirements that's good enough).

I think you'll need to do your own test.

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

 

[SWComposites]

Try searching on the NASA Tecnical Reports server.

 

[Sparweb]

Tests like these do seem more like development tests rather than tests that demonstrate something useful from an aircraft certification point of view.
I've done a few of my own, but, again, just to see what happens. Sometimes there are questions if something fails in a brittle or plastic manner, has long deflections or short, settles to a new shape when relaxed or returns to the original "zero", that only tests can prove beyond a doubt. These deflections usually aren't part of the proof of structure that I'm trying to put forward to people higher up in my company or the aviation authority, so it's not thoroughly documented.

Are you equipped to do tests like the ones you need yourself? Even simple shop tools can be sufficient if you are only looking for general evidence, rather than an exact solution.

STF

 

[WKTaylor]

Teodah...

You are interested in tension fitting design... a fairly complex problem for numerous reasons. NOTE each of the following element contributes ~33% importance to successful Tension fitting design.

Shape. There are fundamental elements to the physical design [shape/material distribution, symmetry/asymmetry, padding, thinning, etc] that affect analysis.

Fastening and bolting. Bolting practices, fastener-pattern layout and surface slope effects [need for tapered washers or spot-facing, etc] have a serious effect on highly loaded tension fittings... especially eccentricities and inducement of secondary bending and stress distributions/concentrations.

Materials. Alloy suitability/temper [FTy/FTu, etc], fabrication method, surface finish, grain quality/orientation, etc... make a huge difference in both elongation/ductility/toughness, yield/ultimate load and fatigue durability.

You may find the following report interesting.

Highly Loaded Airframe Fittings

http://www.dtic.mil/dtic/tr/fulltext/u2/a386666.pdf

Regards, Wil Taylor

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