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-   -   Clean Geometry (http://www.cfd-online.com/Forums/ansa/111853-clean-geometry.html)

_volks_ January 16, 2013 15:18

Clean Geometry
 
Hi, i am new to this forum and i was wondering if someone would be able to help me with my problem.


I am using ANSA 13.1.5 and my problem is with clean geometry.


I am unable to remove overlapping faces even if i use HOT POINTS>RMV OVERLAP, HOT POINTS>CLEAN GEOMETRY OR FACEs>TOPO


The only way that i can fix the issue is if i delete faces and create new ones.

The problem that really intrigues me is that sometimes my geometry check would pass and i would save my work and close the file and then when i would perform the same check later on it would give me new errors... I would get geometry errors even if i would merge several parts together after making sure that each one of them is clean...


In the setting i would use
Settings >
Resolution >
Curves :2
Cons resolution> Length: 2
Distortion Distance: 20%
Distortion angle: 0


Settings>
Tolerances:
HOT POINTS matching distance 0.1
CONS matching distance 0.1



Now i am never sure if my geometry is actually clean or not...are there any other settings or options that i dont know about?


Thank you in advance!

vangelis January 17, 2013 08:41

Hi there,

First I would like to suggest that you move to a newer ANSA version, as v13.1.5 is more than a year old.

I would suggest ANSA v13.2.4.

How do you check your geometry?
Do you deactivate DOUBLE CONS visibility
or do you use the function
CHECK>Geometry?

What options do you have active in Check>Geometry?

_volks_ January 17, 2013 15:40

HI Vangelis, thank you for the quick reply!

I will probably look into upgrading the ANSA version in the future..

I would use the CHECK>Geometry to find the problematic areas and i would select unchecked faces, needle faces, collapsed cons, triple bounds, overlaps and cracks.

Today i was reading "BASIC ANSA Geometry Cleanup and Shell Meshing" after you mentioned DOUBLE CONS visibility and i understand better how to use it now and also how to use release hot points, paste cons, etc..

In the past i've been using ansa for meshing and catia for the surface design but i wanted to speed up the process by using ansa only..

I think what happened probably was that i did not have the same resolution options when i was working on different parts and then when i merged them all together that is why i had more geometry errors.

The biggest problem that i am facing now are the overlapping faces. Sometimes i could be working on a very large part and the whole contour would be overlapping.. The best remedy i had was to import the part in catia and do a healing and a join in the generative shape design bench and then re-import the file in ANSA. However, it can be time consuming and it doesn't work a 100%.

TOPO>HOT POINTS>RM OVERLAP seems like it does not do anything

TOPO>CURVES>SURF INT seems to be working but it it time consuming when there is a more complicated overlap.


My question would be if there is a faster method of fixing overlapping faces since those take the most time to fix.

Thank you for your help.

vangelis January 18, 2013 03:12

Hi there,

By overlapping Faces you mean duplicate Faces I guess.

There is a function, FACEs>RM.DBL (Remove Double)
and it has an option Same Side.

This function will identify if you have duplicate Faces
and it will give you the option to delete one of them.

Sometimes, if the model is complex it is worth while
checking if you have different ANSA PIDs or ANSA Parts.
Using the function Show Only in the PID list and Part Manager
you may better understand how the model looks.

Just to clarify, the function RM.OVERL fixes partial overlaps, not duplicate Faces.

Hope this helps

Vangelis

_volks_ January 28, 2013 13:03

Hi Vangelis,

So finally the problem was that the midskins were still linked to the outer surface of the parts so that is why the rm overlap function did not work..

I used faces>convert to convert the linked faces into actual geometry and after that i am able to clean it using ANSA functions.

Thank you for all your help

vangelis January 28, 2013 17:18

I am glad you've worked it out!

Vangelis


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