Leise, undeutliche Aussprache.

That orangutan with rushs face on it had me rolling they actually did recover quite a few large pieces of the hull intact you can see them On the coast guard video from the way the channels were sheared right off the titanium rings they now think although the carbon fiber hull was a bad idea it was actually the connection point of the 2 materials and the adhesive they think because titanium and carbon fiber expand and contract at different rates that finally the cyclic fatigue lead to water being able to penetrate that joint leading to catastrophe. looking at the way the channel the hull was sitting in and the way it was sheared clean off that solid ring of titanium the amount of force it would take to have a clean shear like that is just incredible although it is likely they knew things were going bad for a short period of time before the implosion dying before your brain can register pain compared to suffocating on the ocean floor with 4 other men doesn’t sound so bad. What’s most heart breaking is the 19 year old he had serious reservations about it but he sucked it up and went anyways because it was Father’s Day really this entire tragedy can be boiled down to one word Arrogance.

kzbin.info/www/bejne/r6fLo6iYmLiGiLMsi=v1mo57MafOBuErbu

11:08 Yeah thats about right

Vielen Dank für die Labor- und Vorlesungsvideos! Werden noch weitere "Folgen" hochgeladen? :-)

please, can you share the script which including steel cage and stirrups

What is Epsylon-dot-star? How does the middle argument become equal to 1?

Excellent

There are very good reasons why we don't see concrete trusses being used.

Hello sir. Could you show how to do nonlinear analysis with material imperfection for a flat plate composite shell? I changed the elastic modulus of the material for a small region and tried to get result in Abaqus. But, Abaqus cannot solve nonlinearly.

Could you kindly confirm if the result for the 4 point bending test on plain concrete, showing a stress of 0.3 MPa and a deformation of 0.0002 , is correct,? considering that the 4 mm displacement method was applied?

This is the best channel about the FEM I have ever seen. Thank You Dr Wagner!

I have a question please ! Do you use a research licence of abaqus or an academic one ? I tried with an academic one and I got this message " Teaching licence couldn't be used with subroutines"

Now its hard to find intel one API 2022 version for both base and HPC. Has anyone tried intel 2025+ VS2022. ifort compilers are dumped and ifx is released by intel and no clue how to link it Alternatively if anyone can share on googledrive Intel Base and HPC 2021 or 2022

I'm curious about whether if I write a script to create an assembly, I should always write a def, and how I can ı use the array command under assembly in scripting.

Good job. Thanks

hello sir. can we import deformed assembly in abaqus for second analysis. Its fine that we can import deformed parts what about deformed assembly

How do you partition outer circle?

Here you use the strain value 0.2% times the ultimate strain, then conclude the stress as the yield stress. But, why you don't use the stress corresponding to strain 0.002 as a yield stress directly? This method is used in Material mechanics text book.

Hi Dr. -Ing, I faced a problem that there is no auto-updating of the Python scripting in the Abaqus.rpy from my end. Did you enable any function in the CAE environment in order to achieve this? As with mine, the Abaqus.rpy file remains empty before and after. The only way I can obtain the scripts is through Macro recording now. Hope you can explain your method. Many Thanks!

Nice and quick to the point. Very nice, thank you.

At 54:20 you show depth/ strain plots but the strain is mV. Is the gage factor known to convert to actual strain. The change is about 700 mV from 0 to 3800 m. By my calcs, the cylinder hoop strain should be .002 to .0025.

Nothing interests me more than finding out which part of them was crushed first.😅

Dr-Ing, Ronald, here is a video that I hope you take interest in... ''snap buckling" kzbin.info/www/bejne/h367ep53eLCngrs and in my private room, I have a model (I will release it after our elections, November 6 or so). But, I think you can work with this video... The report I used is from fiberglass and is from the 70's

The chimp washing socks killed me bro 🤣 😂

They used the wrong adhesive. Great work here ! 👍

The fibers are wound like thread on a spool not wound like a laceration. Please, fix the pronunciation. Btw, I read somewhere that Boeing engineers suggested they have 45° cross directional laminate layers so if a layer failed, the cross directional would help it survive.

Thanks for the video! Could you please share about how to calculate C2, C3, C4 parameters (Characteristic elastic-plastic buckling resistance factor ) using GMNIA calculations as per Eurocode 1993 1-6? Because, it is not clearly mentioned in the Eurocode.

@dr-ing, Ronald, can you please run your numbers with just the hemispheres without the interface rings? My thinking is, the interface rings and bolted connection gave rigidity to each other ... What would each behavior like if the bolts were not a factor? - would they oval in shape??? For context, in one of the reports, they mentioned "ovaling" and I think this is more yiur wheelhouse than mine... Could each section withstand the psi without the bolted connectors ... I have considered the "cylinder-piston pressure from the ends, trying to buckling the carbon fiber hull and therefore the bolts are "useless "... But, ovaling is mention in the report and i am thinking, some point during the implosion (the carbon fiber buckled) and this sudden "release of pressure " created a huge "over pressure " and the interface rings and the end domes "ovaled (during that event)... Because the report identifies the "oval", this means the section that ovaled is now plastic (revealed by the fact that it is in the report as oval shape)...

I don’t understand. I would think plastic buckling occurs when p_plastic<p_elastic, or lambda<1. Why is it <1.73 = sqrt(3).

the CEO of Oceangate refused to build a successful test model. Regardless of known dangers, Oceangate built the full scale vehicle, and immediately began selling expensive tickets for an "Explorer's Club" adventure.

Great Video and presentation analysis ! Thank you ! J

youtube hid this from me til today. god will punish......

I assume it will be impossible to exactly replicate the Titan implosion due to the fibers being sanded down, and thereby changing the strength properties of the carbon fiber hull. We can't know in hindsight exactly where those fibers were sanded down, and exactly by how much. And then the resin or glue was apparently unevenly applied by hand, which will also be impossible to replicate. It's like trying to replicate a kid's carved bark boat. The piece of bark will never be exactly the same, and the carving by hand will never be exactly the same.

It might be a good idea to put the language of the video to English. KZbin's auto translation thinks the language is German, so the subtitles are not working.

Interesting analysis. I don't know if you said it but apparently the titanium domes were downgraded from titanium grade 5 to titanium grade 3. Stockton Rush did that to save money.

Most german english ever heard.

Maybe you should do a forensic analysis of your audio equipment.

how to do display all layer this analysis?

se most realistikk....

Könnten Sie Knallkopp bitte Deutsch reden?

If they can't free them from the ocean gate they need a free Diddy

That was interesting, thank you for sharing

What do you think of the loud bang that was heard near the end of dive 80?

The fiber placed hull looks better but is it “obviously” better quality. The fiber is placed without tension. It is autoclave cured 5 times thru the thickness. During the autoclave cycle the thickness is compacted, reducing the diameter and causing wrinkles.The wrinkles on the outside of the hull are numerous as is seen in a picture in this video. Recently it was shown the wrinkles go deep into each 1” layer. The wrinkles were ground smooth before the next layer, cutting several plies in the process. This not only reduces the compressive strength, it severely affects the local stiffness. Whereas the geometric middle surface is nearly exactly cylindrical, the local stiffness deviations causes the stiffness middle surface to be wavy in the wrinkle regions, which are very numerous. So the buckling capability will be reduced.I would have scrapped this hull after the first autoclave cure. Without the autoclave, it would have looked like Swiss cheese. The filament wound hull is wound with tension in the hoop direction and develops about 1 psi interface pressure with the mandrel per ply. That adds up to 400 psi, but won’t be that high due to compaction. If the mandrel is stiff enough, the positive hoop tension will be maintained to the end. They don’t autoclave composite pressure vessels. I saw someone try it and it did just what this one did and failed prematurely. I’ll put my money on this one to out perform the pretty one. There’s not much difference in the hand and machine placed axial plies.

He made three successful trips. Probably figured he knew more then the other experts

I love how you recognize the crash site, but the failure mode from the animation doesnt match it at all. The window didnt collapse inward. It got thrown outwards by the hull tearing on its join to the front titanium ring.

Interesting. I wonder about your hexagonal structure and if it was inside of a cfrp cylinder, providing some reinforcing of the cylinder, how it might change the modelling. Keeping the internal volume the same as the Titan, with the same wall thickness of the cfrp cylinder or better. My intuition says it should help considerably, but I realise intuition can be wrong.

Very interesting. As stated in the Q and A period, where the ends of the shell mated (by bonding) with the end hemispheres, there is a combination load that must be accounted for. In the center of the shell, hoop stress should be the driving load for design, but at either end a bending load is introduced when the shell and end caps don't strain identically. The longitudinal fibers pick up this load. In the design of the shell, hoop stress should be evaluated against compression allowables, and checked for buckling. Only the circumferential fibers can be used in those calculations. Buckling under hoop stress would be evaluated by assuming that the successive circumferential plies are all concentric. However, they are not concentric after the first few plies, they are budged outward, and some of those plies were actually sanded off during fabrication. Therefore, in the as-build condition, structural calculations would have to include post buckling analysis, with knockdowns inluded for the prosity, resin starved conditions, disbonds and contamination in the layup. Watching the video where the end rings were bonded to the shell made me want to pull my hair out. But, that said, I suspect that the sheared flanges on the rings were secondary to the implosion, which is consistent with your FE illustration. I agree with you that the strain gages warned the operators that the shell was degrading, which they rationalized away. They would have been of no use in alerting the operator that an implosion was imminent. I'm suggesting that the shell failure was due to buckling. When the shell wall started to buckle, total collapse would have progressed instantaneously. I haven't heard anyone suggest that "cracks" in the composite might have allowed water to seep in, which, upon expansion due to freezing, would have extended the defect with eact freeze/thaw cycle. With the state of the debris recovered being so poor, I'm not sure the NTSB guys would be able to find evidence of it. Love your work. Thanks.

Have you modelled this with a solid laminate to account for transverse shear effects, given this is not a thin-walled structure?