This tiny submarine 2.4 miles under the sea, visiting the relics of RMS Titanic. Can it be found and the crew saved before the air runs out?

[Bonefish Blues]

And not autoclaved IIRC

 

[lazybloke]

Here's a clip of Cyclops 2, aka Titan being made. Gluing the titanium end ring onto the CF tube with a buttering of (presumably) epoxy made me shudder.


View: https://www.youtube.com/watch?v=4PUTbK5AqY8

Haven't watched it yet, but your summary makes me shudder. I'm no materials expert but this is all sounding incredibly 'diy' for something that needed to operate faultlessly at extremely high pressures. Strain gauges in the carbon fibre tubes would be of little help if an end ring joint failed.

 

[Bonefish Blues]

Haven't watched it yet, but your summary makes me shudder. I'm no materials expert but this is all sounding incredibly 'diy' for something that needed to operate faultlessly at extremely high pressures. Strain gauges in the carbon fibre tubes would be of little help if an end ring joint failed.

But the water pressure would mean that once down to X feet, that end cap was being pressed against the tube with huge, and increasing force, so why is this a specific concern?

 

[lazybloke]

But the water pressure would mean that once down to X feet, that end cap was being pressed against the tube with huge, and increasing force, so why is this a specific concern?

Pressure would also be pushing 'in' through the epoxy, plus the different materials could be flexing by differing amounts causing undesirable stresses.

 

[Ming the Merciless]

But the water pressure would mean that once down to X feet, that end cap was being pressed against the tube with huge, and increasing force, so why is this a specific concern?

The titanium, epoxy, and carbon fibre would compress and decompress at different rates under the changes in pressure and temperatures encountered during each drive. The titanium would likely recover due to being below elastic limit, but the carbon fibre and epoxy would likely develop signs of fatigue. Small gaps in the materials would begin to appear and get bigger with each dive.

The epoxy and carbon fibre are unlikely to be homogeneous, and thus predicting their elastic and fatigue limits near impossible

 

[ClichéGuevara]

But the water pressure would mean that once down to X feet, that end cap was being pressed against the tube with huge, and increasing force, so why is this a specific concern?

I am in no way an expert so this could be nonsense, but as the pressure is in all directions, so pushing the end caps against the carbon fibre is one thing, but there will also be pressure at 90 degrees to the joint, which could cause slippage as both materials will not react the same and may not 'spring' back to their original size once compressed.

 

[rockyroller]

debating the ridiculous. it failed, end of story

while we're at it, lets throw some screws into the experimental hull. what could possibly go wrong?

View: https://youtu.be/VaOVYkWgpcM

 

[slowmotion]

I am in no way an expert so this could be nonsense, but as the pressure is in all directions, so pushing the end caps against the carbon fibre is one thing, but there will also be pressure at 90 degrees to the joint, which could cause slippage as both materials will not react the same and may not 'spring' back to their original size once compressed.

I'd be worried about the peel strength of the glue line as one component flexes against the other.

 

[Ming the Merciless]

Some debris brought ashore

https://apple.news/AUHLUAM3TRxaq-h-fDEdpzA

 

[icowden]

I'd be worried about the peel strength of the glue line as one component flexes against the other.

I'd be worried about the fact that every other deep sea submersible is spherical and engineered to an incredible degree of precision. There must be a reason why they didn't go for a cylinder...

 

[Mad Doug Biker]

I'd be worried about the fact that every other deep sea submersible is spherical and engineered to an incredible degree of precision. There must be a reason why they didn't go for a cylinder...

It was 'experimental'. Also, as has been said upthread, they wanted to carry the number of people that they did or more. Had it been a traditional spherical example, it would have weighed too much and cost clearly was a factor too.

Oh and they were a bunch of awful eejits.

 

[rockyroller]

Some debris brought ashore

https://apple.news/AUHLUAM3TRxaq-h-fDEdpzA

& the only things they are pulling up, are made of ... wait for it ... metal

 

[Beebo]

Some debris brought ashore

https://apple.news/AUHLUAM3TRxaq-h-fDEdpzA

I’m Impressed they bothered to recover the parts.
The plexiglass in the port hole is missing.

 

[Bonefish Blues]

I’m Impressed they bothered to recover the parts.
The plexiglass in the port hole is missing.

I don't see either of the ti end pieces, one of which contained the window?

 

[Reynard]

But the water pressure would mean that once down to X feet, that end cap was being pressed against the tube with huge, and increasing force, so why is this a specific concern?

Shear force at the join. You've a weak boundary between two different kinds of material (titanium and CFRP) with very different inherent properties. It will cause what's known as a stress raiser, and it's at these points where failure is likely to occur.

Don't forget, we're not dealing with point loads here, but with a load acting equally across the entire surface of the object.