Discussion Forum

Posted: 2 decades ago 13 gen 2010, 11:53 GMT-5

The way I can think of is to duplicate your geometry One as a2d axi where you put all the axixymmetric application and the other one in 3d for the 3d application and then defines the proper coupling variable between them JF

Posted: 2 decades ago 13 gen 2010, 14:49 GMT-5

Hi you can also use the axisymmetric 2D part to quickly construct your 3D by mesh revolving, but for simplest the model (w.r.t. mesh elements) a 2D axie linked to 3D is better, and you learn a lot about linking geometries, which is important to ba able to simplify complex models Good luck Ivar

Posted: 2 decades ago 13 gen 2010, 18:17 GMT-5

Thanks to both of you for your help. It sounds like I can make two models, on axisymmetric and the other 3D, and couple them together. If I understand your suggestions, it looks like keywords would be "coupling" and "linking." Corrections or other keyword suggestions are welcome. Or maybe even better would be a hint on where to find a sample of a model that ties two geometries (i.e. axisymmetric and 3D) in structural mechanics, if it exists. Thanks again. I'll see what I can dig up, and I might be back with more questions.

Posted: 1 decade ago 29 gen 2011, 13:23 GMT-5

[QUOTE] Thanks to both of you for your help. It sounds like I can make two models, on axisymmetric and the other 3D, and couple them together. If I understand your suggestions, it looks like keywords would be "coupling" and "linking." Corrections or other keyword suggestions are welcome. Or maybe even better would be a hint on where to find a sample of a model that ties two geometries (i.e. axisymmetric and 3D) in structural mechanics, if it exists. Thanks again. I'll see what I can dig up, and I might be back with more questions. [/QUOTE] One year later, revisiting the same problem, but with COMSOL 4.1. I never figured this out in COMSOL 3.5, either. I can define a general extrusion coupling in my 2D model. I can't figure out how to link that up to the 3D model. I have spent hours searching for examples and reading the help on extrusion coupling... seems like one side of the coupling is well covered, but no one seems to mention the second side. I know I'm overlooking something, but it really shouldn't be this hard to figure out. Thanks...

Posted: 1 decade ago 30 gen 2011, 04:11 GMT-5

Hi One year later I havent either had the occasion to try it out for my own, but I'm convinced it works (with two coupled models). I can propose that you follow a COMSOL course : a) a generic one and ask the question ()provide the demand previously) for the exercice part. b) Or you organise a specific course at your location (depends how many COMSOL users you are) or c) you get COSMOL to provide a first example. I have used the two first cases sucessfully, and a few times proposed the subcontracting of COMSOL for some specific model build-up, unfortunately the latter did not happen, because we were not selected for the project contract, but I'm ready to start again ;) -- Good luck Ivar

Posted: 1 decade ago 30 gen 2011, 09:07 GMT-5

Thanks Ivar. I did #1 last February; my question wasn't answered completely, then my job responsibilities took me away from COMSOL for some months. A very similar problem arose recently giving me the need to couple 2D and 3D geometries. I think that one of COMSOL's biggest features (multiphysics and coupling) could be documented a bit better, allowing one to learn those features when they need rather than arranging and waiting for the next opportunity to take a class. Dave

Posted: 1 decade ago 28 apr 2011, 02:53 GMT-4

what do you mean and how do you defines the proper coupling variable between a 2D and 3D model with comsol 4.1? best regards

Posted: 1 decade ago 28 apr 2011, 05:43 GMT-4

hi like adding more "simple" examples of the extrusion coupling variables ? ;) Try it on simple examples, once understood it becomes rather "trvial" but I agree it takes time to get to that level, I do not yet feel fully "pro" there either -- Good luck Ivar