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Fillet in 3D?

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Hi,

Is there a way to add a fillet to the common edge of the cylinder and ellipsoid in the attached file (Comsol 4.2a) other than exporting the geometry, open it in a CAD software, add the fillet and export it again? I tried for a while using a 2D workplane where the function "fillet" is available to generate the fillet in 2D and then sweep it along the common edge of the cylinder and the ellipsoid in 3D, but without success (Comsol does not manage to create a union at the end).
Adding a fillet in 3D seems to me like a basic feature which is available in any CAD software.

Thanks for any help.

Alois


8 Replies Last Post 4 dic 2015, 10:06 GMT-5
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 26 nov 2011, 10:16 GMT-5
Hi

Indeed adding a fillet seems easy, in fact it's topologically tricky, and I have too noticed that the fillets are only available in 2D in COMSOL.
I mostly use my external CAD programme as that goes much quicker for complex volumes, then I add if required only spheres and cubes with Comsol, once the CAD is imported, i.e. to mimic an air volume, or to close the caps of a tube
There are ways to get around, for many cases, by union and differences, but it takes some time to figure out the riht way for different cases, and not always on our line of priorities.

Personally, I prefer to have COMSOL excellent on physics and FEM, and poorer on CAD, as I would never use COMSOL for my mechanical drawings, anyhow so why pay twice ? ;)

--
Good luck
Ivar
Hi Indeed adding a fillet seems easy, in fact it's topologically tricky, and I have too noticed that the fillets are only available in 2D in COMSOL. I mostly use my external CAD programme as that goes much quicker for complex volumes, then I add if required only spheres and cubes with Comsol, once the CAD is imported, i.e. to mimic an air volume, or to close the caps of a tube There are ways to get around, for many cases, by union and differences, but it takes some time to figure out the riht way for different cases, and not always on our line of priorities. Personally, I prefer to have COMSOL excellent on physics and FEM, and poorer on CAD, as I would never use COMSOL for my mechanical drawings, anyhow so why pay twice ? ;) -- Good luck Ivar

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Posted: 1 decade ago 26 nov 2011, 10:40 GMT-5
Hi Ivar,

thanks a lot for your quick reply. Of course, I would neither build complex geometries in Comsol. The point is that I want to test different length and depth of this ellipsoid, i.e., run a paramteric study. Is there a way to construct this geometry in Comsol with the length and depth of the ellipsoid as parameters, then by a link to Solidworks have this fillet done in Solidworks, and then simulate it in Comsol using a parametric study (i.e., for every iteration of the paramtric study Comsol would need to comunicate with Solidworks to have this fillet done)?
I have to point out that I am runing Comsol 4.2a on a linux server, and that I have Solidworks installed locally on my PC. I do not know if it is possible to establish a link between Solidworks on PC and Comsol on a Linux machine via the network.

Thank.

Alois
Hi Ivar, thanks a lot for your quick reply. Of course, I would neither build complex geometries in Comsol. The point is that I want to test different length and depth of this ellipsoid, i.e., run a paramteric study. Is there a way to construct this geometry in Comsol with the length and depth of the ellipsoid as parameters, then by a link to Solidworks have this fillet done in Solidworks, and then simulate it in Comsol using a parametric study (i.e., for every iteration of the paramtric study Comsol would need to comunicate with Solidworks to have this fillet done)? I have to point out that I am runing Comsol 4.2a on a linux server, and that I have Solidworks installed locally on my PC. I do not know if it is possible to establish a link between Solidworks on PC and Comsol on a Linux machine via the network. Thank. Alois

Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 26 nov 2011, 11:13 GMT-5
Hi

that is why I run finally Windows OS as then I can link SW and COMSOL easily (with Livelink), by defining "equations" and named variables in SolidWorks, I can then control them from COMSOL, and have the geoemtry updated (with explicit external Parametric sweeps)

--
Good luck
Ivar
Hi that is why I run finally Windows OS as then I can link SW and COMSOL easily (with Livelink), by defining "equations" and named variables in SolidWorks, I can then control them from COMSOL, and have the geoemtry updated (with explicit external Parametric sweeps) -- Good luck Ivar

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Posted: 1 decade ago 26 nov 2011, 17:38 GMT-5
Hi,

I have it working now :-)

My Windows machine does not have the computing power I need. That's why I run Comsol on a Linux server. So what I did was to start a Comsol server on my Linux machine, a Comsol client on my Windows machine and SolidWorks on my Windows machine. Comsol client and SolidWorks communicate via LiveLink, and Windows and Linux communicate via client/server.

I can now run a paramteric study of a geometry which is updated in SolidWorks and then sent to Linux for simulation. Isn't this an amazing feature of Comsol?

Thanks Ivar for your suggestions.

Alois
Hi, I have it working now :-) My Windows machine does not have the computing power I need. That's why I run Comsol on a Linux server. So what I did was to start a Comsol server on my Linux machine, a Comsol client on my Windows machine and SolidWorks on my Windows machine. Comsol client and SolidWorks communicate via LiveLink, and Windows and Linux communicate via client/server. I can now run a paramteric study of a geometry which is updated in SolidWorks and then sent to Linux for simulation. Isn't this an amazing feature of Comsol? Thanks Ivar for your suggestions. Alois

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Posted: 1 decade ago 29 nov 2011, 04:20 GMT-5
Hi Ivar,

I do not find how to control a fillet in SolidWorks from Comsol. There is no variable name associated to a fillet in SolidWorks, in contrary to a dimension in a sketch for example. Do you know how I can asign a variable name to a fillet in SolidWorks?

Thanks a lot.

Alois
Hi Ivar, I do not find how to control a fillet in SolidWorks from Comsol. There is no variable name associated to a fillet in SolidWorks, in contrary to a dimension in a sketch for example. Do you know how I can asign a variable name to a fillet in SolidWorks? Thanks a lot. Alois

Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 30 nov 2011, 12:08 GMT-5
Hi

it's true that a fillet is only "simulated" in SOLIDWORKS so you need to define carefully the ful profile, so there is quite some sweeping there too (I had forgotten about that ;)

Thanks for the linux-windows trick, unfortunately in my case I run both OS on the same WS so I cannot have both up simulataneously (without tweaking and anyhow I loose a lot of RAM) So I'm stuck to Windows for the time being, but it works also

--
Good luck
Ivar
Hi it's true that a fillet is only "simulated" in SOLIDWORKS so you need to define carefully the ful profile, so there is quite some sweeping there too (I had forgotten about that ;) Thanks for the linux-windows trick, unfortunately in my case I run both OS on the same WS so I cannot have both up simulataneously (without tweaking and anyhow I loose a lot of RAM) So I'm stuck to Windows for the time being, but it works also -- Good luck Ivar

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Posted: 1 decade ago 1 dic 2011, 07:47 GMT-5
Hi Ivar,

I tried your suggestion by defining the profile of my fillet on a sketch, and then sweep this profile along the edge to be filleted. Unfortunately, this did not work because the edge to be filleted does not present a constant geometry (the fillet needs to adapt in function of the angle between the two faces defining the edge).

But I found out that the radius of a fillet is also available via a variable in SolidWorks. For a dimension in a sketch, you would typically use "MyLength@sketch1" in Comsol. For a fillet, you can use "D1@fillet1" (where fillet1 is the name of your fillet). It's as simple as that :-)

Regards,

Alois
Hi Ivar, I tried your suggestion by defining the profile of my fillet on a sketch, and then sweep this profile along the edge to be filleted. Unfortunately, this did not work because the edge to be filleted does not present a constant geometry (the fillet needs to adapt in function of the angle between the two faces defining the edge). But I found out that the radius of a fillet is also available via a variable in SolidWorks. For a dimension in a sketch, you would typically use "MyLength@sketch1" in Comsol. For a fillet, you can use "D1@fillet1" (where fillet1 is the name of your fillet). It's as simple as that :-) Regards, Alois

Jeff Hiller COMSOL Employee

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Posted: 9 years ago 4 dic 2015, 10:06 GMT-5
Update on this thread: Nowadays COMSOL does include a direct 3D filleting capability in the Design Module (See www.comsol.com/design-module). A screenshot of you file with the added fillet is attached.
Best,
Jeff
Update on this thread: Nowadays COMSOL does include a direct 3D filleting capability in the Design Module (See www.comsol.com/design-module). A screenshot of you file with the added fillet is attached. Best, Jeff

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