• comicallycluttered@beehaw.org
    link
    fedilink
    English
    arrow-up
    0
    ·
    1 year ago

    Let me also point out that carbon fiber composite doesn’t yield, it just fails catastrophically

    I actually have a question about this because I saw someone on YouTube speaking about this two days before the debris was discovered (the channel is Sub Brief, and they were going through all the things wrong with the vessel and how it likely imploded).

    With metal/steel/other alloys (forgive me, I’m not familiar with the engineering, hence my question), when they implode, it’s straight up crushed, right? Like force on a tin can.

    In the video I mentioned, the guy was saying that carbon fiber doesn’t crack; it’s like porcelain (I think he said, or another fragile material) and it just shatters completely.

    So I’ve been curious about something. The implosion that this submersible suffered, what would it have looked like?

    If the hull just shattered under pressure, would the implosion be more like hundreds of thousands of shattered pieces ripping apart everyone rather than “crush” them in the “traditional” sense (and they’d be immediately crushed anyway by the water pressure regardless)?

    Or would the implosion still present itself more or less the same as it would with a steel(?) hull?

    It feels almost worse if they were, for lack of a better term, shredded. I know that it would still be instantaneous, but it feels like… I don’t know, much more visceral.

    • tentphone@lemmy.fmhy.ml
      link
      fedilink
      English
      arrow-up
      0
      ·
      1 year ago

      I have done destructive strength testing on carbon fiber. It would not shatter like porcelain. Carbon fiber is made of thin, very strong but very flexible stands of carbon embedded in more brittle resin (plastic). The resin by itself probably would shatter. Carbon fiber will snap suddenly as the resin fails, but the fibers keep it from flying apart.

      With steel, it would depend very much on the alloy. Some are very ductile (will bend very far without breaking) whereas some are more brittle and actually will shatter with enough force.

      This video gives a good idea of how steel would compare to carbon fiber. Carbon fiber starts at 3:57 and high speed steel (a very brittle steel) at 6:19. There is no ductile steel, but 6061aluminum at 2:48 fails pretty much the same way just with a lower force.

      https://youtu.be/ifOzrOgpI4g

      • comicallycluttered@beehaw.org
        link
        fedilink
        English
        arrow-up
        1
        ·
        1 year ago

        Thanks for that! I’ll check it out.

        Appreciate the knowledge on the various materials. I probably misinterpreted the carbon fiber thing from the video.

        And looking at the inside of the sub after I posted that comment, I also noticed how much material surrounds that carbon fiber (I don’t know if that’s the composite or some kind of insulation).

        Semi-related, they also had the monitors screwed into that on the inside, which I’m guessing would be very bad if it reached the carbon fiber interior?