[ChocolateManiac]

Hi, this is my first posting on this web-site. I'm new to Star-CCM+, and I'm currently working on a project with floating body. I have to create floating bodies and connect them with flexible beams.
I did create Floating bodies with Parts-Blocks.
Here is the problem. I have no idea with creating 'flexible beams'. These beams have to bend(not in a great degree, just little according to the outer forces like created wave on Star-CCM+) and should be connected with the blocks at the top of the blocks. Inserted Images show my situation.

In brief,
1. Is there any way to create 'Elastic' beams in Star CCM? If is, how can I create it?
2. Can I connect Blocks and this created beam?
3. Can I control the flexible property in Star CCM? ex) by controlling Young's Modulus, E?

Thanks for help in advance.

[Peresvet]

Originally Posted by ChocolateManiac

Thanks for help in advance.

Of course you can. Don't give up hope. There are several options. You can set the stiffness of the cable connection, you can connect it with a beam with axial hinges. And of course, you can include the beam in the strength analysis by assigning a section and material.
I have given links here many times to my calculations with visualization. Now I don’t give it, because they consider it self-promotion. Stupid, yes, but this is how the WORLD works.

[SESP]

Hi,

this is going to be pretty complex. I would try to split up your problem and proceed step by step.

First of all, you need the DFBI motion of the floating bodies. That is not complex, you will find good documentation for such cases. In my experience, it requires a lot of fine tuning until the floating bodies are actually floating and until the simulation is running stable. Personally, I would start with one floating body consisting of your arrangement of the two connected bodies. You can model them in the CAD modeler if you dont have them, that should be an easy task.

Once the DFBI floating body is running properly, extend your case towards FSI. You will need the solid continuum mechanics solver. Honestly, I have never used it in combination with DFBI, so its going to be interesting how that will be possible. For a classical FSI simulation, you can specify solid properties as you mentioned, so in principle this is not a problem. With FSI, you also open a farily big box which will require careful adjustment of the case until its running stable. In my experience, it takes some time until you are capable of representing the deflections, even if they are moderate. Eventually you will need an automatic remeshing process when the mesh quality becomse too bad.

So all in all a very complex task, in particular for someone new to STAR-CCM+. My main advice is to try to break down the problem into smaller units you can handle.

Good luck,
Sebastian

[ChocolateManiac]

Wow, thanks for your kind advice! If it's alright, may I ask you one more question?
After posting this post, I have tried some methods to solve this problem and got some advice from other source. Now I'm trying to solve this problem with coupling Star-ccm+ and Abaqus. I found that I can do FSI using this method.
But I can't find good documents or thesis treating this method. If you can, can you recommend some papers or thesis?

[SESP]

Hmm no sorry, I don't have any papers in mind for that.
If you have access to the Siemens support portal, you will find some very good documentation there including examples on coupling STAR-CCM+ with Abaqus. So that would be my first source to look at.

In principle, I think that coupling STAR with Abaqus doesn't necessarily help for your problem. It makes it more complex because you now are coupling STAR with an external solver. It is technically no problem, but a more complex workflow. For the simple mechanical problem you should find all that you need in the continuum mechanics solver from STAR, so I don't see the point of involving Abaqus (although superior for mechanical in general) for this problem. I would try with the simpler way first and once you have set up the problem correctly, you can still try to replace the STAR mechanical solver with Abaqus...