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Eigenfrequency Analysis with a hole in the structure

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Dear all,

I am trying to make a very basic Eigenfrequency analysis. I have attached geometry which has a cylindrical hole in the middle. However Comsol wants me to assign a material through the hole as well where the hole suppose to be void.

Although I bypassed this problem by assigning Air into the hole and defined Poisson's ratio and Young's Modulus as zero, I am not sure if it is a proper solution.

I thank you in advance for your help, Best regards,



2 Replies Last Post 06.12.2017, 10:29 GMT-5
Jeff Hiller COMSOL Employee

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Posted: 7 years ago 06.12.2017, 08:56 GMT-5
Updated: 7 years ago 06.12.2017, 08:58 GMT-5

Hello Osman,

If you do not want to solve any equation in a particular part of your geometry (here, your cylinder), you should simply remove it from the geometry (Geometry>Boolean Operations>Difference).

If you need to solve some equations but not others in a part of your geometry, you need to be a bit more subtle and assign different domains to the different physics interfaces. From your post, this does not appear to be your case, but I am mentioning this for others who may read this thread some day.

Best,

Jeff

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Jeff Hiller
Hello Osman, If you do not want to solve any equation in a particular part of your geometry (here, your cylinder), you should simply remove it from the geometry (Geometry>Boolean Operations>Difference). If you need to solve some equations but not others in a part of your geometry, you need to be a bit more subtle and assign different domains to the different physics interfaces. From your post, this does not appear to be your case, but I am mentioning this for others who may read this thread some day. Best, Jeff

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Posted: 7 years ago 06.12.2017, 10:29 GMT-5

Thank you very much for your response Jeff!

Actually I tried the "Difference" and I had the same problem. However I have just noticed that, "Keep input objects" were thicked under the Difference. I am sorry.

Thanks a lot again,

Best, Osman

Thank you very much for your response Jeff! Actually I tried the "Difference" and I had the same problem. However I have just noticed that, "Keep input objects" were thicked under the Difference. I am sorry. Thanks a lot again, Best, Osman

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