Discussion Forum

Posted: 1 decade ago Mar 7, 2011, 7:00 a.m. EST

Hi I have noticed this error when I mesh complex domains, particularly those with topology looping around an object (torus like). My way around is to: 1) cut the domain into simpler parts and mesh by sections 2) mesh edges or faces around critical region 3) start from centre outwards, and start with parts containing details in fine mesh then use coarser mesh around Mostly I get around like that, sometimes I must cut further my geometry into smaller parts, by adding internal boundaries Note: use latest version, the mesher handler is one of the features improving with the new releases -- Good luck Ivar

Posted: 1 decade ago Mar 7, 2011, 11:41 a.m. EST

Thanks a lot ,sir.

Posted: 1 decade ago Mar 7, 2011, 3:04 p.m. EST

I tried to make the modifications mentioned.But the same problem still persists.I am attaching the model with this post.It would really be helpful to get some help on the same.Best regards,Thanks in advance.

Attachments:

• curved plates with guard electrodes.mph

Posted: 1 decade ago Mar 8, 2011, 2:01 a.m. EST

Hi with such a symmetric geometry you are better off working only in 1 quadrant (1/4 or even 1/8) of the geometry and then revolve your system or work with mirror operations. Also with such thin features you must mesh rather dense to avoid that the elements inter penetrates. Also you should put a cylinder all around your fine model. Finally I would use a sphere as external air boundary, and not a cube, you have less corners -- Good luck Ivar

Posted: 1 decade ago Sep 2, 2011, 4:43 a.m. EDT

[QUOTE] Hi I have noticed this error when I mesh complex domains, particularly those with topology looping around an object (torus like). My way around is to: 1) cut the domain into simpler parts and mesh by sections 2) mesh edges or faces around critical region 3) start from centre outwards, and start with parts containing details in fine mesh then use coarser mesh around Mostly I get around like that, sometimes I must cut further my geometry into smaller parts, by adding internal boundaries Note: use latest version, the mesher handler is one of the features improving with the new releases -- Good luck Ivar [/QUOTE] Hi everybody, I've got this problem: "Failed to respect boundary element edge on geometry face". I've imported the geometry in a CAD format and it's quite complex. I decided to convert the geometry into COMSOL format, before making 'Form Union'. I meshed all the boundaries, playing with the element sizes and toggling between General Physics/Fluid Dynamics/Plasma. However, when I try to mesh the volumes, COMSOL gives me the error message that I stated above. Should I edit the CAD geometries? Isn't there any other solution to get around this? I thought that, once the external boundaries of an object was meshed, I was pretty straightforward to mesh its inside! Thanks for any help! Prisca

Posted: 1 decade ago Sep 2, 2011, 4:44 a.m. EDT

[QUOTE] Hi I have noticed this error when I mesh complex domains, particularly those with topology looping around an object (torus like). My way around is to: 1) cut the domain into simpler parts and mesh by sections 2) mesh edges or faces around critical region 3) start from centre outwards, and start with parts containing details in fine mesh then use coarser mesh around Mostly I get around like that, sometimes I must cut further my geometry into smaller parts, by adding internal boundaries Note: use latest version, the mesher handler is one of the features improving with the new releases -- Good luck Ivar [/QUOTE] Hi everybody, I've got this problem: "Failed to respect boundary element edge on geometry face". I've imported the geometry in a CAD format and it's quite complex. I decided to convert the geometry into COMSOL format, before making 'Form Union'. I meshed all the boundaries, playing with the element sizes and toggling between General Physics/Fluid Dynamics/Plasma. However, when I try to mesh the volumes, COMSOL gives me the error message that I stated above. Should I edit the CAD geometries? Isn't there any other solution to get around this? I thought that, once the external boundaries of an object was meshed, I was pretty straightforward to mesh its inside! Thanks for any help! Prisca

Posted: 1 decade ago Sep 2, 2011, 3:19 p.m. EDT

Hi normally COMSOL tells you on which face/edge Id it fails, locate the items and try a manual meshing of the face or edge first then et COMSOl continue, often it works out. If this is for several edges/faces, you must iterate trough all until you have a correct mesh. Defeaturing is often easier in the CAD, be sure holes/bolts threads ... , fillets and champfers are reduced to a minimum in the CAD BEFORE you load it into COMSOL -- Good luck Ivar

Posted: 1 decade ago Jan 14, 2014, 9:54 a.m. EST

Ivar, you're the best! Just found this old thread and it really helped me resolve the aforementioned problem. Dividing my domains into several smaller domains and then meshing them successively using multiple "Free Thetraedal" steps worked instantly. Kind regards David

Posted: 1 decade ago Mar 30, 2014, 4:00 a.m. EDT

Hi, I was wondering if anyone on this thread might be able to help me with a different mesh error I have been having - I also have multiple domains, and since they are very different sizes I created three different meshes for four domains (two domains are in the same size range). I keep getting the following error: No mesh on domain 3 in geometry 1, mesh case 0. No mesh on domains 2 4 in geometry 1, mesh case 0. Not all domains are meshed. I created the three meshes and hit "build all" for each one (though I think even once would have probably been enough?) but for some reason it seems to think only the first domain is meshed. Does anyone recognize this error and know what may be causing it? Thank you, Shoshana

Posted: 1 decade ago Apr 28, 2014, 6:13 p.m. EDT

Hi, A similar thing happened to me and I found out there are actually some very small domains in my model that I didn't intend to create! They were tiny domains between two domains that were ALMOST touching. Under the 'mesh' node, go to where the errors are explained and click on the domain number in the box; it'll show you where the domain is and make sure there are no hidden domains that you're missing. Could you also attach your geometry so I can see how it looks like? Best, Dana

Posted: 1 decade ago Apr 30, 2014, 3:18 a.m. EDT

Hi, Thanks so much for your response - I actually recently figured out what the problem was. I knew what domains I had but I created individual meshes for each one, and COMSOL apparently doesn't like that. The solution was to use the same mesh node for all domains and add one "free tetrahedral" node, and then under that node I added my three different size nodes for the three different areas. That was it understood that everything was meshed as one action, but I was still able to do different sized meshes in different domains. Thanks again! Shoshana

Posted: 1 decade ago Nov 6, 2014, 1:08 a.m. EST

Hello, I am making a model of a microchip that has multiple layers. To be particular, it has a silicon layer, an oxide layer on top of that, followed by nitride, and two more. They are essentially cuboids placed on top of each other. I am trying to mesh each domain before I add the next one on top. However, when I try to mesh the second domain (oxide), I get the error message : The face is locked by adjacent domain mesh and cannot be remeshed. Is there a way around this? Thank you in advance for your help!!

Posted: 1 decade ago Nov 22, 2014, 1:07 p.m. EST

Thanks for posting your solution. I had the same issue and that fixed it!

Posted: 10 years ago Dec 26, 2014, 3:47 a.m. EST

Hello G S Could you please explain step-by-step how you did the meshing sequence? Thanks