6 ms·

There are now many reports about material fatigue as the primary cause, but I am not so sure. Another article [0] mentioned that the building is currently analy

• abduhl 4y ago
  Why would you expect the forces acting on the glass to be ill-distributed if the enclosure were tilted slightly? Water pressure acts hydrostatically. The enclosure appears to have a circular cross section. As long as the tilt is not severe there is no reason to believe anything other than tensile hoop stresses due to equal circumferential loading will develop.
  • a4a4a4a4 4y ago
    The normal force of the tank wall to the floor will shear across the acrylic if it's not perfectly flat. Pressure outwards is normal to the tank wall relative to the water, but if this force goes diagonally through the floor, that's bad.
    • abduhl 4y ago
      If the tank burst due to it shearing off of its base then it is not the glass that has the problem; it’s the connection to the base. This might sound pedantic but the OP said the forces on the GLASS were ill-distributed. The most important part of after the fact disaster analysis from an engineering context is being excruciatingly specific about the performance of structural elements.
      • upsidesinclude 4y ago
        If you wanted to be pedantic you would correct the statement because there is no glass. To be excruciatingly specific.
        • abduhl 4y ago
          The article refers to the aquarium as glass throughout it.
          • kayodelycaon 4y ago
            The material used is plexiglass, aka acrylic, a type of clear plastic. Actual glass is probably too brittle or expensive. People use "glass" to mean the clear part of a window, not the actual material, in this context.
            • abduhl 4y ago
              I'm glad to hear that you'd agree with me then that a correction saying "there is no glass" would be inappropriate because when someone says glass they mean the clear part of the tank.
              • seattle_spring 4y ago
                This may or may not be your intention, but fyi you are coming off as extremely condescending bordering on /r/iamverysmart level tones. I'm no expert, but I know that a hot tub on slightly uneven ground has a good possibility of bursting and ruining the tub due to how much stress the water will unevenly put against a side. I don't see why the same underlying reasons wouldn't apply here too.
            • upsidesinclude 4y ago
              Plexiglas® A trade name.
      • lqet 4y ago
        But isn't the overwhelming majority of the glass material connected to the base by the glass itself (namely the glass below it)?
  • bombcar 4y ago
    I would expect it's not the tilted slightly that would matter but simply settling after installation - a settling foundation can crack concrete and glass so stresses could change if the foundation of the tank was moving.
  • jacquesm 4y ago
    That all depends on whether the underlying surface is still perfectly flat around the perimeter. If it is not then you get local stress variations that can lead to catastrophic failure. The seams between the panels are likely also not designed to be loaded that way. Just the asymmetrical load on the structure could do the trick at a relatively small angle because it might cause the structure to get compressed against something bordering it. This is not a trivial engineering project.
• swader999 4y ago
  The hotel was told to lower their temperatures. With cold weather outside the differential between the tank and the lobby is the most likely cause.
  • jacquesm 4y ago
    That's a good guess, but I'd still like to see the final report if and when it is published and whether or not they manage to find the root cause. Likely the differential made the problem worse to the point that something gave but I suspect that there is a deeper underlying cause that made it sensitive to that difference in temperature to begin with. Either a material flaw, an assembly issue or something else.
    • fuzzfactor 4y ago
      Seems to me it must have been a salt water tank if it had clownfish, and they are tropical so it's not just exposing the acrylic to constant warm water, but a more realistic marine environment. In the lab I've chemically tested acrylics that were bullet-resistant at low-cm window thickness. No bullets were used in my phase of the operation, but I was clipping off chips from the exact coupons which had been physically measured beyond the fracture point. You can tell there's a difference in ductility and brittleness with temperature. Pretty tough stuff regardless. In the aquarium these are supposed to be very thick-walled acrylic curved panels bonded together. If the water was maintained warm enough for the reef fish while the ambient air dropped below freezing I don't like that idea. The entire temperature differential being borne by the thickness of the acrylic could mean there are different plastic properties diverging among the inner and outer surfaces of the "glass" panel. This could give rise to stress being concentrated deep within the panel if the transition is not too smooth. Conditions like this could be recreated if so. Might have been OK if they had penguins and cold-water fish this time of year.
    • swader999 4y ago
      I'm basing it off of what this guy is reporting. He seems to have an inside legit view. https://www.zerohedge.com/user/105370 https://www.zerohedge.com/user/105370