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Evaluating cross sectional areas of a hollow tube at distances along length?

Creator
Creator

I have a hollow tube with varying OD and ID throughout its entire length along axis X. Is there a way in NX for me to see the cross sectional area of the tube at specific increments along the X direction?

 

The "Section Analysis" tool doesn't seem to have the cross sectional area option, and the "Section Inertia Analysis" doesn't seem to function with hollow tubes either. It either gives me an error saying "hollow shapes are present" or "no sections could be analyzed. Is the section object face the cross sectional surface or the surface along the length? 

 

Attached is an example of the tube I am trying to analyze. In this case, the cross sections should be parallel to the YZ plane and normal to the X axis. Thanks!

3 REPLIES

Re: Evaluating cross sectional areas of a hollow tube at distances along length?

Gears Esteemed Contributor Gears Esteemed Contributor
Gears Esteemed Contributor

At the "select face" step, turn on the "body faces" selection rule so that all the faces of the body are selected.

Re: Evaluating cross sectional areas of a hollow tube at distances along length?

Creator
Creator

Thanks, that worked perfectly. Didn't realize that all the surfaces encompassing the body must be selected. On another note, how do you update the analysis when changing dimensions? In the NX documentation here, it states the following:

 

"The software also creates annotations for each section. They all belong to one analysis object. This makes it easier to delete or hide the analysis. When you modify the parent faces, the software updates the analysis."

 

It is my understanding that the "annotations" mentioned here refers to the PMI notes that are created for each section measurment that displays the section area. However, upon manually changing the ID and OD, the notes don't change the section area. Is there a button to update the analysis?

 

EDIT: Is there also a simple way to export this data to excel? I'd like to be able to make external calculations using these areas and continually update them as the model geometry changes.

Re: Evaluating cross sectional areas of a hollow tube at distances along length?

Gears Esteemed Contributor Gears Esteemed Contributor
Gears Esteemed Contributor

On the few occasions that I have had need of the section inertia analysis, I have NOT seen the values update in response to a change in the model. I thought it was a static measurement, I did not realize it was supposed to be dynamic until I re-read the documentation in your link. It is quite possible that I'm doing something wrong, but I don't see any way to force an update (even "update for external change" doesn't update the analysis note). The other possibility is that the documentation is wrong; perhaps it was written for planned features that didn't make it into the final product. I'd suggest contacting GTAC to see how to make the notes dynamic (then post the answer here so I can learn the trick too Smiley Happy).