Crush Depth for an Empty AL80?

[Chugwhump]

so what would the crush depth be for a solid steel soccer ball?

Gonna need a rocket ship to the nearest black hole I think.
Toss it in, and let's see what happens.

Chug
Cheated on the physics final.
Got a "C", and ran out of the room.

 

[g2]

so the smaller the object (advantage to the sphere) and the thicker its "wall" the more pressure it takes to crush it, right? so a solid steel tennis ball would be far more resistant than a solid steel soccer ball?

Yes and yes (for balls of the same wall thickness). It comes down to how efficiently the enclosure distributes the pressure. A sphere is the most efficient shape.

A larger enclosure (bigger diameter) has less of a curve to it, so Steve_C's comment about the strength of an arch is essentially correct. A small, tight arch is most structurally sound.

You guys really have too much time on your hands.

Nope. We just prioritize!

 

[knotical]

... so a solid steel tennis ball would be far more resistant than a solid steel soccer ball? ...

I'm uncertain, so I'll ask: by "solid steel", do you mean a steel ball such as a ball bearing which is steel throughout? Or do you mean a ball with air inside whose wall is all steel? If the former, I'd say with confidence it would not crush. If the latter, it would depend on the thickness of the wall. And yes, for equally thick walls, the smaller diameter tennis ball would be be more crush resistant.

 

[H2Andy]

I was thinking of solid balls, varying only in size

 

[g2]

I was thinking of solid balls, varying only in size

Oh. Well those probably won't crush at any depth. ...No internal air-space to crush into.

 

[knotical]

I was thinking of solid balls, varying only in size

Ah, then it wouldn't be imploding, but actual shoving of atoms closer together. I'm almost certain either would sink to the ocean floor unharmed. Would probably need Chugwump's black hole to see. In which case I can say with confidence "I don't know".

 

[H2Andy]

right, of course

but if the ocean were a supernova ...

I'm shutting up now

 

[Bob DBF]

According to the math on this site (which is based off research by Wood's Hole OI), an AL80 made out of 6061 aluminum, with a wall thickness of .521" and an OD of 7.25" should yield at about 3500 meters and buckle at about 5750 meters.

Confused, normally the yield depth would be the crush depth of the object, the buckling would happen shallower.


Bob

 

[KeithG]

The related Underwater Experiment Canister Project is almost exactly what I'm trying to do: find a cheap way to enclose sensors for very deep oceanographic use. I'm thinking I might be able to cut an AL30 in half, mill an end-cap (from another AL30?) and add O-rings or epoxy to make an
economical enclosure.

Yur doing it wrong!

The solution is simple - put your sensors in a baggy full of oil. Nothing to compress. No compression failures. It can go all the way to the bottom.

Uwatec computers have demonstrated this principle for many years. They do not have to resist compression since they are solid. No air inside.

 

[SFLScubapro]

Call up Jamie and Adam, and let's start a new thread... "I'd like to see a scuba tank explode... UNDERWATER." =)

Now, that would be epic!

MS