Henrik Sönnerlind
COMSOL Employee
Please login with a confirmed email address before reporting spam
Posted:
5 years ago
11.02.2020, 01:07 GMT-5
Updated:
5 years ago
11.02.2020, 01:20 GMT-5
Hi Theodore,
The reason Continuity is not available for boundary-to-boundary in the Shell interface is that the degree of freedom values should not be equal. Thickness and offset must also be taken into account.
You can solve your problem in two different ways. One is to use contact with adhesion, and having the adhesion being always active. The other one is to connect the degrees of freedom using an extrusion coupling operator mapping from one boundary to another. You then prescribe the displacements and rotations on one side in terms of those on the other. Rotations should be equal, while the displacements will also contain terms from the mid-surface distance and rotation.
The situation you describe is however interesting. We will look into adding a more natural 'Continuity-like' condition for modeling it.
Regards,
Henrik
-------------------
Henrik Sönnerlind
COMSOL
Hi Theodore,
The reason Continuity is not available for boundary-to-boundary in the Shell interface is that the degree of freedom values should not be equal. Thickness and offset must also be taken into account.
You can solve your problem in two different ways. One is to use contact with adhesion, and having the adhesion being always active. The other one is to connect the degrees of freedom using an extrusion coupling operator mapping from one boundary to another. You then prescribe the displacements and rotations on one side in terms of those on the other. Rotations should be equal, while the displacements will also contain terms from the mid-surface distance and rotation.
The situation you describe is however interesting. We will look into adding a more natural 'Continuity-like' condition for modeling it.
Regards,
Henrik
Please login with a confirmed email address before reporting spam
Posted:
4 years ago
17.02.2020, 09:35 GMT-5
Hej Henrik,
Appreciate the reply. I tried the approach described related to adhesion.
Thing is, the model for an eigenfrequency analysis shows mode shapes that are separate. For each eigenfrequency only one domain from the whole assembly has a mode shape. It seems as the eigenfrequencies are calculated for each part separately. I used extra pairs so as to restate previous continuity from each domain union but with or without them the results remain the same. I believe I have checked all parameters so could you provide your opinion about it.
Thank you for your time
Hej Henrik,
Appreciate the reply. I tried the approach described related to adhesion.
Thing is, the model for an eigenfrequency analysis shows mode shapes that are separate. For each eigenfrequency only one domain from the whole assembly has a mode shape. It seems as the eigenfrequencies are calculated for each part separately. I used extra pairs so as to restate previous continuity from each domain union but with or without them the results remain the same. I believe I have checked all parameters so could you provide your opinion about it.
Thank you for your time
Henrik Sönnerlind
COMSOL Employee
Please login with a confirmed email address before reporting spam
Posted:
4 years ago
18.02.2020, 03:56 GMT-5
Hi Theodore,
When you combine contact with eigenfrequency analysis, you should run an Eigenfrequnecy, Prestressed study in order to get the correct linearization point for the eigenfrequency analysis.
Regards,
Henrik
-------------------
Henrik Sönnerlind
COMSOL
Hi Theodore,
When you combine contact with eigenfrequency analysis, you should run an *Eigenfrequnecy, Prestressed* study in order to get the correct linearization point for the eigenfrequency analysis.
Regards,
Henrik