Volume body from solid structure 1

[Dan90]

Hi guys,

My part consists of an airbox for automotive applications and I need to get the air volume inside it which, of course, is not present as body. Does anyone know a simple way to obtain such an air volume as a body (starting from the airbox)?


I have attached an image of the airbox structure.

 

[mjjmecheng]

I'm not exactly sure which volume you are referring to, so I'll assume the white part on the left. One thought might be to create an new extrusion in your model that engulfs the existing white box. In creating your new solid, ensure that you do not merge it with existing solids. Then, use a Boolean operator to subtract the existing solids from the new solid that you created.

Inserts \ Combine \ Subtract

From there, you can choose either to keep the tool, the target, or both. The resulting solid will not be a terribly clean looking object as there appears to be a decent amount of ribbing and other geometries that will affect it. However, somewhere in the center of that mass will be the inside volume of the white box which you can then do the following to measure.

Analysis \ Measure Body

Hope that works for you or that it gives you a starting point to move forward with.

 

[Arkance/PhoeNX]

Insert -> Associative Copy -> Extract Geometry.
Set to 'Region of Faces' then you can extract a shell of the interior by selecting a seed face and then a face of the opening as the boundary face.
This will create a sheet body. Cap the hole with a planar surface for example, sew that to the shell and you'll have solid as long there are no other holes.


Anthony Galante
Senior Support Engineer


NX3 to NX10 with almost every MR (21versions)

 

[Toost]

If you have a fully closed volume, there is a feature named "Space finder" ( Analysis - Space finder) which can calculate the volume by "filling it with facet cubes". - There is a accuracy tolerance to this.
You can with the same feature analyse " what happens if i pour 5.5 liters of fluid into this cavity". and then see where the level goes.

Regards,
Tomas

 

[JohnRBaker]

Thru a clever way of using the 'Delete Face' function, you can, in one operation, often get a solid body representing the 'void' inside parts like this. Of course we would need to actual part to show you exactly how to do that, but baring that, if you tell us what version of NX you're running I could perhaps supply you with a simple example showing you how this works.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Digital Factory
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

 

[Dan90]

Thank you guys for the very quick replies.

Excuse me, but maybe I was not able to well explain my real intent. I do not need to just measure the empty volume inside the airbox, but I need to "create" such a volume.

First, I brutally closed the structure by means of the extrusions. Then I tried, as suggested by mjjmecheng, to make a boolean operation with a cube which encolses my airbox structure, but, at this point, I do not know how to move on. Do you have any tips?

I am running version 9 of NX.

 

[Dan90]

In the attached image I use the space finder as suggested by Toost and the filled volume is exactly what I need as a body..

 

[JohnRBaker]

So you've gotten what you need, correct?

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Digital Factory
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

 

[Dan90]

No, I need to create the airvolume in the image as a body..

 

[JohnRBaker]

OK, attaached is a zip file containing an NX 9.0 part file where I've created a solid representing the 'void' or 'air' inside the part. I've also included a video showing you how I did this. If you watch carefully and experiment with my model I think you'll see how this was done and then you could try it on your model. Anyway, let me know how it worked, or not.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Digital Factory
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

 

[Dan90]

Dear John, thank you for the awesome video.

Anyway I did not solve my problem due to an error message which appears when I try to delete the faces.

I have attached a video in which I try to execute the same commands as you did with your part. What do you think is wrong with my procedure?

 

[JohnRBaker]

First I would run Examine Geometry and see what you can learn. Then I would run Part Clean-up. If that didn't do the trick, since your model is not fully featured, I would use the...

Export -> Heal Geometry...

...which will created a copy of your part file but with the model optimized and fixed-up by removing any bad or problematic topology. Then I would try the 'Delete Face' operation again.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Digital Factory
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

 

[Toost]

Adding to Johns tips:
It seems from the video that your model might have more "openings" between the "volume" and the outer shell ?
-If so you must select these openings too, else NX will attempt delete all faces, both interior and exterior.
When selecting the faces to delete, the first pick selects a "region start" from where NX searches for adjacent faces, the next picks selects "Boundary faces" where the searching shall stop, and by this isolate the inner faces from the outer. NX will then use the "last face before the boundary" to try cap the volume. ( It helps if this "last face before" is a planar face and not a complex shape. If so , try cut off or trim or replace to make it planar.)

Another tip, ( I don't know if this will do anything different than the Heal Geometry), under the synchronous ... there is a Optimize Face feature that have made miracles on imported ( other cad systems) data for me.

Regards,
Tomas

 

[Dan90]

Unfortunately, I did not solve my problem yet.

I will let you know if I solve, but, if you have some other tips, please share them with me.

 

[Dan90]

Hi guys,

finally I solved my problem extracting each single volume from each part and then merging all the volumes together.

Thank you very much for the help!