Comments by "BZE-dt6di" (@BZE-dt6di) on "OceanGate Titan Hull - Hundreds of Ill-advised Carbon Fiber Grind Spots" video.

Carbon fibers have high tensile strength. In this case, their use is completely wrong, the stress of pressure is like pushing a string. If the pressure of 400 bars was applied from the inside out, the fibers would withstand it. Pressure of 400 bars from the outside is wrong. Wrap a can of Coca-Cola with string. Will it become stronger? You will dent it in your hand. The pressure from the inside will withstand. Completely inappropriate use of carbon fibers. Excuse my English, I am European.
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His thing was flawed from the get-go. You never use carbon fiber composites in compression. This is basic mechanical engineering. Everyone with a mechanical engineering degree who worked on this thing at all should be banned from engineering for the rest of their lives.
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1000 videos and all useless. The never-ending story of a fool who caused his own death and the death of 4 other people. I don't understand what is still being discussed here. Everything has been wrong from the very beginning. Stockton Rush is an absolute fool to use carbon fiber, which has excellent tensile strength, on a structure that requires a material with high compressive strength. UNDER COMPRESSION!!!! Carbon fiber can't do that. That's as stupid as pushing a child's toy with a string. It's the same extreme as trying to stress concrete in tension. The tensile strength here is minimal. That's why steel rods are put in concrete and stretched with great force to compress the concrete. Prestressed concrete then has great strength, see bridges for vehicles and trains. Using fibers for pressure is a technological crime.
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Carbon fibers have high tensile strength. In this case, their use is completely wrong, the stress of pressure is like pushing a string. If the pressure of 400 bars was applied from the inside out, the fibers would withstand it. Pressure of 400 bars from the outside is wrong. Wrap a can of Coca-Cola with string. Will it become stronger? You will dent it in your hand. The pressure from the inside will withstand. Completely inappropriate use of carbon fibers. Please excuse my english, I'm European.
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I have yet to see anyone stop at the absurdity of wrapping the hull of a submarine with carbon fiber. These fibers have high tensile strength. In this case, however, high compressive strength is needed from the outside! The strongest thread won't do it, that would have to be the pressure inside the submarine and not outside. It's like pulling a string. Or an analogy with the implosion of a large cistern, which can withstand the great pressure of its contents, but when the air is sucked out of it, collapses due to the mere atmospheric pressure from the outside. That actually happened here. The hull, solid under pressure from the inside, collapsed after pressure from the outside. I don't understand. Who invented it? When used in aircraft wings, the fibers are stressed by tension, which they can withstand perfectly, not by pressure. Similar to steel cables in prestressed concrete bridges. Using them on a submarine is a super stupid idea. Try wrapping a coke can with steel wire. Then try to squeeze it. It will go as easily as if the cable was not there. Another thing would be to pump it from the inside, it would withstand high pressure.
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I see several problems. Technical: 1. carbon fibers have high tensile strength, none in compression, completely unsuitable for vessels subjected to external pressure, 2. different thermal expansion of titanium and plastic, 3. completely unsuitable combination of cylindrical vessel and spherical ends, 4. even with such a poor design, technological indiscipline. Human: 1. Stupidity, vanity and inability of the owner to accept opinions other than his, 2. ignoring all safety regulations.
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I see several problems. Technical: 1. carbon fibers have high tensile strength, none in compression, completely unsuitable for vessels subjected to external pressure, 2. different thermal expansion of titanium and plastic, 3. completely unsuitable combination of cylindrical vessel and spherical ends, 4. even with such a poor design, technological indiscipline. Human: 1. Stupidity, vanity and inability of the owner to accept opinions other than his, 2. ignoring all safety regulations.
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Yes, but the 4500 psi pressure is applied from the inside of the container outwards, putting tensile stress on the carbon fibres. If it were applied from the outside, the container would collapse under much less pressure, the fibres have very little compressive strength.
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@SyntaxDaemon Carbon fiber submarines do not exist, there are pressure vessels stressed by pressure from the inside.
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@kayrunjaavice1421 I am a qualified engineer. A carbon fiber scuba tank and other uses are stressed by pressure from the inside out and the fibers are stressed by tension, that's OK. When stressed from the outside, the fibers are stressed by pressure, they have no strength, only the epoxy holds the pressure, the tank collapses inward, implodes. Composite materials with carbon fibers crack very quickly, without much warning, no visible deformation, like metals titanium and others. Wrong from the start, wrong choice of material, wrong shape, wrong combination of materials and bad bonding. Totally inappropriate use of carbon fiber for an externally pressurized vessel, even if 12 out of 10 Boeings recommended it.
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@robertbackhaus8911 When compressed, the carbon fibers have no strength, and the whole hull is held together only by epoxy. It is an example of technical dilettantism. The materials have completely different thermal expansion properties. One visit to a bicycle repair shop would have convinced them this was a terrible design. It is well known that carbon fibre bikes routinely fail where metal parts interface with the carbon fibre components.
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