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Node selection by path

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mj345

Mechanical
Joined
Jan 9, 2019
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82
Location
US
Hello All,

Thank you for every one for answering my questions quickly. I really appreciate all your help.

I have couple of questions,

1. Is there any way to select the nodes by path in orphan mesh part. For example selecting nodes on end edge of circular hole of a body?
2. Is there any option other than *tie to apply between to contact faces. Tie is like gluing together, so looking for any other option as we run linear perturbation all the time?
if I use *contact pair in my model it will become friction less tie because of linear perturbation analysis, If I am correct,please let me know your views.

Kind Regards,
 
When it comes to the first question you can use Create Set —> Node —> Select the nodes for the set: by feature edge.

Tie means that the surfaces can’t have relative movement during the analysis (contact won’t change). Thus it can be used for linear analysis. Contact pairs on the other hand allow for the relative movement so contact changes and the analysis must account for this nonlinearity. You can also use tied contact but tie constraint is better than this. So whenever you perform linear static perturbation analysis, contact can’t change and behaves like tie.
 
Perfect.Thank you FEA Way.
 
Hi FEA Way,

From above discussion I have one more question, Is there any guideline for choosing *Tie or *Contact Pair while doing analysis.
I was practicing for all my analyses that applying contacts wherever the components are meeting together,Please let me know your views.

Kind regards,
 
The general rule is that you use tie when you want your components to be perfectly glued (or welded) together so that they can’t move relative to each other. On the other hand contact is used when you want to include motion - surfaces in contact can slide and separate from each other. In reality most cases would require the use of contact but we often ignore the relative motion when it’s supposed to be rather small and apply tie constraint merging surfaces like they were single part. Also contact is required when surfaces initally aren’t touching but we know (or think) that they will touch in the analysis due to deformation of the model.
 
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