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combination of beam rotor and solid rotor

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Hello everyone I was trying to simulate for a cracked shaft. I want to know if it will be possible to combine beam rotor(for the part of the beam that's fine) and solid rotor(for the cracked part in the shaft) modules together? I was trying this but the system is giving me strange error: "The variable is not compatible with a previously added variable with the same name: root.comp1.rotbm.thtt_tot. - Reason: Sizes differ" Please someone suggest how to do it. I have also tried to use to use same displacement parameters for both the physics by changing the dicretization but it fails.


2 Replies Last Post Nov 2, 2020, 1:52 a.m. EST
Prashant COMSOL Employee

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Posted: 3 years ago Nov 1, 2020, 11:22 p.m. EST
Updated: 3 years ago Nov 1, 2020, 11:23 p.m. EST

Dear Harsh,

Coupling Solid Rotor to Beam Rotor is not straight forward becuase of both modeled in a different referece frames. The Solid Rotor is modeled in a corotating frame and the Beam Rotor is modeled in a stationary frame. Thus coupling also involves frame transformation of the displacements as well as finding the correct map location on the solid. Attached is an example of one such coupling to help you with the set up process. Note that Weak Constraint nodes are used to set up the connection between both. For finding more details, you can write to us at support@comsol.com

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Thanks and regards,
Prashant Srivastava
Dear Harsh, Coupling Solid Rotor to Beam Rotor is not straight forward becuase of both modeled in a different referece frames. The Solid Rotor is modeled in a corotating frame and the Beam Rotor is modeled in a stationary frame. Thus coupling also involves frame transformation of the displacements as well as finding the correct map location on the solid. Attached is an example of one such coupling to help you with the set up process. Note that Weak Constraint nodes are used to set up the connection between both. For finding more details, you can write to us at support@comsol.com


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Posted: 3 years ago Nov 2, 2020, 1:52 a.m. EST

Thank you so much Prashant for the valuable reply. Sir can you please tell what these weak constraints are doing exactly and how they work. Or if you can plz tell me a better way to have more such insights on such methods or couplings. Thanks.

Thank you so much Prashant for the valuable reply. Sir can you please tell what these weak constraints are doing exactly and how they work. Or if you can plz tell me a better way to have more such insights on such methods or couplings. Thanks.

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