Here's a three minute plus video of the test of a Boeing 777 wing, breaking at 154% of design strength, 4 % over requirements. Pretty spectacular. Part of what makes your flying experience safe.
154% of design strength is only 4% over requirments? They designed it not to be strong enough to meet requirments?
Am I missing something?
__________________ 2009: No races, No times. Slow year. So, now you're 96 cals short. You're now in starvation mode. Doomed. - LostDog
Blog entry: November 1, 2009, Pancakes LiveSTRONG daily plate log
154% of design strength is only 4% over requirments? They designed it not to be strong enough to meet requirments? Am I missing something?
As I interpret it: 100% equals strength required for any conceivable flight emergency, the 150 is 50% over that. Note how far the wing is bent up in the test - we all might have heart attacks just from looking were we in the plane - others of us would be cheering!
So is it designed to achieve the 100% then? I am confused as to where the 4% over requirments comes into play is all....
Maybe I am being dense...
__________________ 2009: No races, No times. Slow year. So, now you're 96 cals short. You're now in starvation mode. Doomed. - LostDog
Blog entry: November 1, 2009, Pancakes LiveSTRONG daily plate log
I think you are overthinking this. Say X is the max amount of force that an airplane will encounter. This is probably gathered through all the many years of flight and testing, so the engineers know that an aircraft will encounter certain amounts of wind shear, turbulence, and whatever else is up there. They come up with a number X (I have no clue what X is measured in) and then design the aircraft to withstand 150% of X. The extra 4% sounds like a bonus, that's all.
Are you looking at the standard the plane is built at as being 100%? Such as X=150% of whatever the aircraft will face and also X=100% of the plane's capabilities? I don't know if that's going to come across clearly. In that sense the plane actually surpassed the design standard by 2.67%.
I think you are overthinking this. Say X is the max amount of force that an airplane will encounter. This is probably gathered through all the many years of flight and testing, so the engineers know that an aircraft will encounter certain amounts of wind shear, turbulence, and whatever else is up there. They come up with a number X (I have no clue what X is measured in) and then design the aircraft to withstand 150% of X. The extra 4% sounds like a bonus, that's all.
Are you looking at the standard the plane is built at as being 100%? Such as X=150% of whatever the aircraft will face and also X=100% of the plane's capabilities? I don't know if that's going to come across clearly. In that sense the plane actually surpassed the design standard by 2.67%.
Feel free to ignore my ramblings.
I would think the FAA would look at all the available data and say planes must be able to withstand X.
Engineers would go out and design their planes to be able to withstand X so they can be granted flight approval and be safe to fly.
They way I read it was. design strength = X, Required strength was 50% greater than X and it broke a bit higher than that.
I was like, why would they design X to be less than what it was required to be.
*shrug*
__________________ 2009: No races, No times. Slow year. So, now you're 96 cals short. You're now in starvation mode. Doomed. - LostDog
Blog entry: November 1, 2009, Pancakes LiveSTRONG daily plate log
Almost all standards for testing/performance exceed what will normally be seen by a product - electrical or mechanical. There's no way to account for any and all situations/events so there's an extra 50% built in to compensate. I'd say the extra 4% is more a marketing or sales tool than anything else.
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Two Bears Dadda? Two Bears Benno, just two. ______________________________ ___________
There are three things in my life which I really love: God, my family, and baseball. The only problem - once baseball season starts, I change the order around a bit. ~Al Gallagher, 1971
But would you design it to meet what it would likely be expected to endure or with that 50% added on? ie the 50% added on is actually what it is designed to meet, not what it is likely to encounter.
__________________ 2009: No races, No times. Slow year. So, now you're 96 cals short. You're now in starvation mode. Doomed. - LostDog
Blog entry: November 1, 2009, Pancakes LiveSTRONG daily plate log
I suspect the standard to which it's tested is 150%. So if you want to meet said standard, that's what you test it to.
More than likely, they will do a test to see what the "breaking point" is and that's what the video is. Then the sales and marketing people can use that to say that it goes 4% over the standard.
I'm just guessing here BTW.
__________________
Two Bears Dadda? Two Bears Benno, just two. ______________________________ ___________
There are three things in my life which I really love: God, my family, and baseball. The only problem - once baseball season starts, I change the order around a bit. ~Al Gallagher, 1971
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