Titan Submersible Simulation Gets More Realistic

Titanium rings and acrylic porthole dimensions have been revised.

The following is a transcript of Dr Ronald Wagner’s simulation of the Titan submersible and is published here with his permission. The simulation was redone with revisions to the dimensions of titanium rings and the acrylic porthole. The results now support the intact titanium rings recovered in the wreckage and explain what happened to the porthole, which was not attached to the recovered titanium endcap.

In today’s video, I want to give an update on my OceanGate Titan model. The model is now much closer to the actual structure.

I improved the design of the rings and the titanium hemispheres. Check out these rings and the dimensions of the rings.

We see above the section sketch I have made, the space for the cylinder edge of only 40 mm in depth. Maybe you can comment in the comment section if you have an idea about how deep this feature should be.

I have also updated the dimensions of the titanium hemispheres. They are now much thinner. The thickness is now 3.25 inches or 82 mm, and they have those rings attached as shown.

The other titanium dome looks like above with a porthole window.

I’ve also updated the dimensions of the window. It’s now much closer to the original window,

Images: OceanGate and CompositesWorld.

Images: OceanGate and CompositesWorld.

I often got the question why I defined the CFRP [carbon fiber reinforced polymer] using a cross-ply setup with alternating 0- and 90-degree layers, so I found the reference again. [Ed. note: CompositesWorld’s cross-ply description is of a carbon fiber hull used in previous dives. The cross-ply description of the hull on the fatal dive is not known at this time]. They used a prepreg in the 0-degree direction and wet winding in 90-degree or hoop direction. And I modeled the CFRP cylinder using continuum shell elements.

Here you can see the cross-ply definition.

Above we have a comparison of the old Titan model and the revised model. You can see the length is a little bit different because on the previous model the rings were a little bit bigger. You can see the CFRP cylinder is the same, but titanium hemispheres are a lot thinner.

This doesn’t affect the linear buckling load. We can see above the linear buckling load of the updated model, and it is still like a 100. There’s not a lot of difference because the main dimensions of the cylinder have not changed.

Here we can see the new nonlinear simulation. It starts at 30 MPa because otherwise it takes too much time. The most interesting part happens at around 50 MPa.

This time we have 10 times as many frames. The simulation looks much more realistic in my opinion.

When the fracture, or implosion, happens, the two hemispheres move together and then the window gets blown out.

It was often requested to show the implosion in real time. And this is possible if we go here and select a time history. But it happens too fast. You won’t see any details of the implosion.

Next: Simulation Solves the Mystery of the Titan’s Missing Viewport

About Ronald Wagner

 

Here is my YouTube channel: https://www.youtube.com/@hnrwagner. I have had this channel since 2020. I already have 260 videos, most of which are regarding material models, scripting and buckling imperfections.

Corrected August 12, 2023: Thickness of titanium hull is 3.25 inches. It was 3.75 inches.