How does paper survive?

[p.dath]

I was watching a TV program yesterday called Mayday about airplane crashes. One of the crashes was caused by a murder/suicide by a passenger, and they put the jet into a direct nose dive at full power. The plane hit the ground with a force of 5,000 g (yes, 5,000 times the force of gravity). The plane had exceeded mach 1 at the point of impact.

The impact was so hard that the plane was shredded. The murder weapon, a 44 calibre pistol had it's short barrel broken. They couldn't identify anything that look like a human body or a bit of a body. Everything was pulverized beyond recognition.

Everything - except a lot of paper. In fact, they even found the suicide note. The paper wasn't even torn or marked. The crash site was surrounded by what looked like shrapnel from the plane being ripped apart - and lots of sheets of paper.


I sat there wondering how it is that with the engineering knowledge that society posses that all the different materials failed (under an huge impact load to be fair) but something as flimsy as paper survived undamaged. I'd tried doing some Googling about the forces that paper can withstand, but I mostly came up with unrelated searches (everything is a research "paper").


I did some thinking, and I'm guessing that paper has a very low shear force (which is why you can cut it with sissers and tear it) but can withstand a lot of compression force (try squashing a flat sheet of A4 paper between your hands).

It kind of makes me wonder if paper is really that resilient to huge compression forces that perhaps there is something we have overlooked about it that could be incorporated into other materials to make them withstand considerably higher compression forces.


So, anyone keen to swap their helmet for a paper hat?

[bogan]

I know right, and have you seen the metal paper they make? It's called shim steel, even stronger than normal paper. You know what we need, is to make planes out of this shim steel stuff, maybe we could form it into beams and things with good structural rigidity (which of course would no longer be fit for shims, so would just be called steel), and perhaps rivet more of the thin stuff to it for aerodynamics :innocent:

[BuzzardNZ]

So, anyone keen to swap their helmet for a paper hat?

A wooden one might work. How about you try hollowing out a coconut shell and wear that?

[vifferman]

I sat there wondering how it is that with the engineering knowledge that society posses that all the different materials failed (under an huge impact load to be fair) but something as flimsy as paper survived undamaged. I'd tried doing some Googling about the forces that paper can withstand, but I mostly came up with unrelated searches (everything is a research "paper").

I did some thinking, and I'm guessing that paper has a very low shear force (which is why you can cut it with sissers and tear it) but can withstand a lot of compression force (try squashing a flat sheet of A4 paper between your hands).

Your 'logic' is not very logical, and is in fact flawed (you've thought in the wrong direction). Firstly, if there were individual sheets of paper (unlikely to have been many, apart from passenger lists, documents, etc., they would have survived anyway (short of being burnt) because they have very low mass (and therefore inertia) and a fairly high surface area, yet are very flexible. They were also probably largely unconfined (free to move around), and the shock waves from the impact would have blown them in all directions. Much of the paper present would have probably been torn from books and magazines on board the plane - so there's your shearing).
In any case - other similar low mass, low strength objects would have survived too if present - like unconstrained/unconfined feathers, styrofoam, hair, sheets of cotton, vinyl and other fabric.
The paper isn't that strong, and if confined at the edges (like the sheets of aluminium the aircraft was clad with), would have been subject to tearing, puncturing, etc. (pages ripped from books and magazines).
If you took the same paper, and glued it to other sheets (essentially what 'customwood' is), and made bits of the plane out of it, it would have been stronger, but suffered much the same fate as other materials.

[FlangMasterJ]

Umm because it's paper. Throw a sheet of paper at the ground as hard as you can, what happens? It sails off in random directions then floats to the ground

[Virago]

Vifferman got it in one.

A sheet of paper has low mass, therefore low inertia.

It's the same principle that allows an insect to simply walk away from a fall that would kill a human.

[Banditbandit]

Try Newtonian physics ... F=M x A

M= mass (of the paper) F= Force A= Acceleration ...

So paper is very very light - bugger all mass ... the force = bugger all x the acceleration (or in this case deceleration) ...

Not hard to see how paper survives such an impact

[Big Dave]

Tax invoices and GST receipts.
They possess the same anti-matter as odd socks.

Ubiquitous until actually required.

[Kickaha]

Try Newtonian physics ... F=M x A

M= mass (of the paper) F= Force A= Acceleration ...

So paper is very very light - bugger all mass ... the force = bugger all x the acceleration (or in this case deceleration) ...

Not hard to see how paper survives such an impact


Yeah, try that with your fucking Kindle

[jasonu]

I know right, and have you seen the metal paper they make? It's called shim steel, even stronger than normal paper. You know what we need, is to make planes out of this shim steel stuff, maybe we could form it into beams and things with good structural rigidity (which of course would no longer be fit for shims, so would just be called steel), and perhaps rivet more of the thin stuff to it for aerodynamics :innocent:

No they should make planes, trains and space shuttles out of 'black box' material. That part always seems to survive a crash.

[SMOKEU]

Was that the Pacific Southwest Airlines BAe 146-200?

[skippa1]

A wooden one might work. How about you try hollowing out a coconut shell and wear that?

Thats just silly. A coconut shell is already hollowed out

[BuzzardNZ]

Thats just silly. A coconut shell is already hollowed out

Fair point, I meant getting out the milk and flesh.

I think I'll stick with my Arai for now :oi-grr:

[skippa1]

Fair point, I meant getting out the milk and flesh.

I think I'll stick with my Arai for now :oi-grr:

It may work.....the sizes would be limited to children and midgets

[p.dath]

Was that the Pacific Southwest Airlines BAe 146-200?

I think that was the one.

[Akzle]

Fair point, I meant getting out the milk and flesh.


then it would be a coconut, not a coconut shell.

Shoot a phonebook.
With x tonnage of aircraft falling ontop, i doubt paper would survive. Unless, as other scenario, it was free to leave.

[SMOKEU]

I think that was the one.

I remember that episode. I still don't know why the 146 has 4 turbofans, instead of 2 that are usually on this size aircraft. Being a regional jet it's not like ETOPS are going to be a factor.

[huff3r]

I remember that episode. I still don't know why the 146 has 4 turbofans, instead of 2 that are usually on this size aircraft. Being a regional jet it's not like ETOPS are going to be a factor.

To reduce noise. They can produce more thrust for less volume by using four smaller engines rather than two larger ones.

Also gives better short field performance, which is important considering it goes a few places no aircraft of similar size can.

[Fastmark]

Yeah, try that with your fucking Kindle

Love it:clap:

[Banditbandit]

Yeah, try that with your fucking Kindle

http://robinsafblibraryblog.files.wordpress.com/2011/12/a-library-card-can-take-you-anywhere.gif?w=549&h=411

[Erelyes]

I know right, and have you seen the metal paper they make? It's called shim steel, even stronger than normal paper. You know what we need, is to make planes out of this shim steel stuff, maybe we could form it into beams and things with good structural rigidity (which of course would no longer be fit for shims, so would just be called steel), and perhaps rivet more of the thin stuff to it for aerodynamics :innocent:


No they should make planes, trains and space shuttles out of 'black box' material. That part always seems to survive a crash.

Planes that could survive 1500g would give rise to the newest worst job in the world.

Cleaning the inside of the plane afterwards.

[oldrider]

I was watching a TV program yesterday called Mayday about airplane crashes. One of the crashes was caused by a murder/suicide by a passenger, and they put the jet into a direct nose dive at full power. The plane hit the ground with a force of 5,000 g (yes, 5,000 times the force of gravity). The plane had exceeded mach 1 at the point of impact.

The impact was so hard that the plane was shredded. The murder weapon, a 44 calibre pistol had it's short barrel broken. They couldn't identify anything that look like a human body or a bit of a body. Everything was pulverized beyond recognition.

Everything - except a lot of paper. In fact, they even found the suicide note. The paper wasn't even torn or marked. The crash site was surrounded by what looked like shrapnel from the plane being ripped apart - and lots of sheets of paper.


I sat there wondering how it is that with the engineering knowledge that society posses that all the different materials failed (under an huge impact load to be fair) but something as flimsy as paper survived undamaged. I'd tried doing some Googling about the forces that paper can withstand, but I mostly came up with unrelated searches (everything is a research "paper").


I did some thinking, and I'm guessing that paper has a very low shear force (which is why you can cut it with sissers and tear it) but can withstand a lot of compression force (try squashing a flat sheet of A4 paper between your hands).

It kind of makes me wonder if paper is really that resilient to huge compression forces that perhaps there is something we have overlooked about it that could be incorporated into other materials to make them withstand considerably higher compression forces.


So, anyone keen to swap their helmet for a paper hat?

Notice how when you flush everything goes except the damned skidmarked paper? .... Usually floats right back up .... sunnyside up of course! :shit::facepalm: flush flush flush :angry2: