787/A350 - did they test the wings to destruction ?

[NWSRG]

Of course, I meant 'destruction'!

We've all seen the video of the 777 wing being tested to it's limit...but did Boeing ever break the 787 wing? Or Airbus the A350 wing?

Just curious as to what the final limits were in either case...


(Title fixed for you - JT)

[DIBO]

I suspect your Google is broken, better buy a new one....

6ofhc5dDiCE

And er, construction comes before destruction if you want to test something

[NWSRG]

DIBO, I had never seen that before. I knew they tested a scaled down test piece at some stage, but had never seen it...thanks! But, NOT a full scale test...

As for 'construction'...well, the fingers just did their own things despite what the brain was thinking!

[CONSO]

Uhhh- that video was of the wing box and about 1/2 of a full scale 787 wing. AFIK a full scale wing test to destruction was not done- but was loaded to a few percent above ultimate load. test to destruction is NOT required. However you can find full scale load tests to destruction of the boeing 747 and 777 on the boeing site. 767 was not loaded to destruction because of a aft frame partial failure which twisted the vertical stabiliser section about 15 degrees. FWIW the 777 wing test to destruction actually broke- failed within a few inches of predictedf location by buckling near an inboard rib.

[NWSRG]

Thanks Conso...the video speaks of a "full scale, half span" test. So not the full test (as per 777). This was what I remembered...thanks for clarifying!

So, not on the 787, but what about the A350?

[CONSO]

Thanks Conso...the video speaks of a "full scale, half span" test. So not the full test (as per 777). This was what I remembered...thanks for clarifying!

So, not on the 787, but what about the A350?
Check the airbus site- if they did- I'm sure it would be available along with data

[underfire]

A350, full scale aircraft test, not just a wing..
even with pressurising the tube

https://www.youtube.com/watch?v=B74_w3Ar9nI

Typically, Boeing tests the wings and components separately, while Airbus tests entire assemblies. This also is the case with the the aerodynamic design, which is why the wingbox between the two looks so different.

[CONSO]

" Typically, Boeing tests the wings and components separately, while Airbus tests entire assemblies.'

Partly right- mostly wrong. While BA does test some items separately, they always test two complete structures.

One airframe is used for a static test of a complete but non flyable structure to ultimate- wings, body- usually but not always to destruction when the wings are bent up to failure. . The other is a fatigue test - wings, body pressurized, etc to simulate a typiical takeoff and cruise and landing cycle. Go to the Boeing site for some facts and data.

for example

Static test complete (http://www.boeingblogs.com/randy/archives/2009/11/static_test_complete.html)

Boeing Moves 787 Dreamliner Fatigue Test Airframe to Testing Rig - Feb 02, 2010 (http://boeing.mediaroom.com/2010-02-02-Boeing-Moves-787-Dreamliner-Fatigue-Test-Airframe-to-Testing-Rig)

https://www.youtube.com/watch?v=Ai2HmvAXcU0

https://www.youtube.com/watch?v=UFSh04Zl4Yw (https://www.youtube.com/watch?v=UFSh04Zl4Yw)
"
LiveLeak com Boeing 787 Dreamliner Wing Loading Test-- its the 777 !


note the video labeled 787 is actually the 777 wing test in 1995 - I wuz there !!

[riff_raff]

The purpose of structural load testing is to validate the analysis results for the structure at a given load case. In some cases, a smaller analysis factor of safety (FOS) is permitted if the analysis is validated by structural testing.

Testing a structure to failure, beyond its design limits, is not typically required. But it sure is exciting to watch.

[CONSO]

For a pretty good summary- photo of 787 structural test to 150 percent go here-
no video but great photo of wings bent to ' max '

https://www.wired.com/2010/03/boeing-787-passes-incredible-wing-flex-test/

and
here

http://www.seattletimes.com/business/boeing-aerospace/boeing-analysis-shows-787-passed-wing-bend-test/

[tdracer]

Testing a structure to failure, beyond its design limits, is not typically required. But it sure is exciting to watch. During the original 767 type cert, the plan had been to test the wing to failure. But the wing was stronger than expected - while well above the predicted wing failure loading, part of the fuselage failed where it was being held down. Since they were already above the required wing loading, the decision was made not to repeat the (rather expensive) test to failure condition. Hence the 767 wing was never tested to actual failure.

We immediately accused the structures guys of building the wing too heavy :E

[barit1]

I went on the Boeing visitor tour in 1983 IIRC, rode the elevator up to the 747 assy observation platform, etc. - Still an amazing sight!

But outside the building was the 767 test article in the fatigue test rig. Over and over, the wing was flexed to the cert limit, then relaxed back to unload it. It didn't break while we were there, and I'm sure they interrupted the test every couple hundred cycles for routine inspection.

[CONSO]

Thanks for the update-confirmation of my earlier post # 4 which I said . . . 767 was not loaded to destruction because of a aft frame partial failure which twisted the vertical stabiliser section about 15 degrees.

From memory- a frame near the aft door had either been omitted or improperly fastened and failed. I was working on 767 at the time in tooling. Later after it had been hauled out to the ' boneyard ' I had to go out and check what special tool ( hilock cutter ) might be needed to unfasten the last two fasteners on the aft portion of the upper plus chord ( wing to body join ) to allow trimming about 2 inches off the upper horizontal / vertical portion due to a possible fatigue issue noted in early analyis of the ongoing fatigue testing. Other than the partially buckled aft section, the rest of the plane appeared to be in good condition with few if any obvious deformations.

[CONSO]

The fatigue test article is cycled to duplicate near max loadings of takeoff- cruise- landing- pressurization /depressurization cycles as in commerical service. Not expected to fail wings or any other parts but to find and if needed to correct structural issues resulting from many service cycles . And yes- includes routine inspection cycles.

It is NOT the same test structure used in static test

" But outside the building was the 767 test article in the fatigue test rig. Over and over, the wing was flexed to the cert limit, then relaxed back to unload it. It didn't break while we were there, and I'm sure they interrupted the test every couple hundred cycles for routine inspection."

[underfire]

" Typically, Boeing tests the wings and components separately, while Airbus tests entire assemblies.'

Partly right- mostly wrong. While BA does test some items separately, they always test two complete structures.

BTW, the image you provided was for the drop test, not a fatigue test as noted by the thread subject. Again, while Airbus does a cyclical fatigue test on the entire airframe, Boeing does a wing test, not including the wingbox and fuselage...

I did say typically. I was actually referring to the design and research. It is well known that Boeing designs the wings and models them individually, as they do not consider the fuselage/wingbox in any lift capacity, while Airbus does, hence the much different wingbox design.

[CONSO]

" BTW, the image you provided was for the drop test, not a fatigue test as noted by the thread subject."

??????? That POST both a static test and a fatigue test airframes - what do you mean by ' drop test' ?

Once again- Boeing uses two ' non flyable' - early production ( line number less than 4 or 5 ) for full up static and full up fatigue tests. The static test bird has full wings ( no feathers ) and fuselage stressed- loaded to 150 percent for certification- and depending to a few percent above until failure

On the fatigue test bird ( non flyable ) the complete body and wing unit are flexed and pressurized simulating typical flight profiles for tens of thousands of cycles.

As to design philosophy- you may be correct- but what does that have to do with subject of thread. ???

Please provide link to image you calim was a ' drop test '
The first image Of the first lInk was labeled as loading the fatigue test bird- one can clearly see the multiplehoses used for rapid pressurization and depressurization.

" "Unlike static tests, where loads are applied to the airplane structure to simulate both normal operation and extreme flight conditions, fatigue testing is a much longer process that simulates up to three times the number of flight cycles an airplane is likely to experience during a lifetime of service," said Scott Fancher, 787 vice president and general manager, Commercial Airplanes. "This testing is instrumental in confirming the longevity of the airplane."



Thank you

[barit1]

tdracerWe immediately accused the structures guys of building the wing too heavy

Sinilarly attributed to Gerhard Neumann of GE. "If the test article works correctly the first time, it's too heavy!"

[vilas]

barit1
You had replied long time ago on using MCT with AEO. The same discussion is on again. Would you reply on that thread again?

[riff_raff]

The primary structures of a commercial aircraft are analyzed for something like 50 or more load cases. But the structural/fatigue tests are only performed to validate 2 or 3 of those analysis cases.

The 787 wing box had some issues during its initial structural qual testing.

DailyTech - Boeing Dreamliner Wing Box Problems May Delay Program Further (http://www.dailytech.com/Boeing+Dreamliner+Wing+Box+Problems+May+Delay+Program+Furthe r/article15840.htm)