Finns en del intressanta kommentarer till den video jag länkade ovan.
Här kommer kritik på hur slafsigt tillverkningen gick till, både av röret och limningen.
Citat:
Aerospace engineer and former submariner here.
I'm shocked at the uncontrolled environment used to assemble the hull, especially when the main cylinder was wrapped, and also when the hemispheres were then adhered to the wrapped carbon fiber hull...literally a warehouse with dust and other loose debris (human hair) floating around, uncontrolled humidity, etc.
They also mixed the epoxy by hand...ugh. This would normally be performed in a humidity-controlled Class 10,000 clean room at the very least, with bunny suits for the assemblers.
The entire manufacturing process was a mess...which implies so were a lot of other things with this ill-fated submersible.
Röret komprimerades dubbelt så mycket som titanet, vilket leder till påverkan i fogen mellan dessa två.
Citat:
bout a year ago, Thunderf00t did a video about the Titan.
He focused especially on the compression modulus of the carbon-fibre composite in comparison to that of the titanium. Not knowing the exact composition of the materials used for Titan, he used representative compression modulus figures from engineering sources online.
What he suggested is that, at 400 atm, the CFC was deforming to about twice the extent that the titanium was.
Given that the connector ring was a sleeve on the outside of the CFC cylinder, this put an incredible tensile load on the epoxy they used.
At the time, this was obviously conjecture, but it was reasoned out quite logically.
The failure mode you describe quite closely matches Thunderf00t's conjectured failure at the interface between CFC and titanium.
Titan täcks av ett oxidskikt, detta bör avlägsnas innan man limmar, man har då en begränsad tid på sig innan ny oxid bildas.
Citat:
I worked as an optomechanical engineer . When I worked for Kodiak Graphic we used titanium rings to create the focus lens stack.
The 3 lens & 3 rings were bonded together with UV cured adhesives.
Titanium forms a surface oxide layer that is not well adhered to the surface. To get the adhesive to correctly bond to the titanium, the oxide layer was removed by pickling it in hydofluoric/nitric acid mixture then stored in IPA.
Once the ring was removed from the IPA the clock was ticking until too much oxide had formed rendering the surface unacceptable for bonding.
Don't see or read that anything like this was done to the end rings.
The front ring is missing CF shards so this looks like a simple debonding failure.
Mer kritik över hur limningen gick till.
Citat:
You overlooked the fact that they were not glueing the end caps in a sterile environment.
All it would take is dust, bits of skin or a hair in the glue to affect its strength.
They did it in a dirty hangar with 50 people stood watching shedding all that off their bodies so their seal probably wasn’t ideal
Kritk över hur röret lindades.
Citat:
As someone who's doing a masters in carbon fiber composites, one thing I want to mention that no one talked about is how they did the carbon fiber layup.
It looks like it was laid up like a coil pot or a single wall 3D print with all the fiber in the hoop direction. That poses two important problems. one is that it has to take axial stress and there are no fibers in that direction to support it, carbon fiber pressure vessels are ideally a +-55 degree layup because the hoop stress is twice the axial stress. The second major problem is that there is only one fiber direction through the whole thickness, which makes it really easy for cracks to propagate through the full thickness in the matrix, and even worse, the interface between the layers, which is even more prone to cracking, runs through the thickness.
Finns många fler intressanta kommentarer, jag rekommenderar er att läsa dessa.
Skickar med länken igen för säkerhets skull.
https://youtu.be/CxBtZmyPzVA?si=QVy5JoYJcPdj6yy4
