Mapping Elements to Surfaces for Symmetric Plies
Altair EmployeeHello everyone,
I have a question that I don't know if it's possible to solve this way but, here it goes anyway.
The model I'm trying to optimize using Optistruct is a wing loaded with a pressure on its top skin. It has a symmetry plane along the XZ axis. You can see this below:
<?xml version="1.0" encoding="UTF-8"?>
This is the base geometry of the wing imported to Hyperworks through an STP file.
<?xml version="1.0" encoding="UTF-8"?>
Here, you can see the symmetry plane displayed on CATIA.
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The load is a pressure that I apply on the surfaces I want and then I map them to the nodes corresponding to the surfaces using BC -> Loads on Geometry
See below:
<?xml version="1.0" encoding="UTF-8"?>
The pressures applied to the surfaces
<?xml version="1.0" encoding="UTF-8"?>
The mapped loads after using BC -> Loads on Geometry.
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After running a free sizing optimization the result I get for the plies is not completely symmetric (although I constrained my design variables to be symmetric). See below:
<?xml version="1.0" encoding="UTF-8"?>
As you can see, to the edge the ply is definitely not symmetric.
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So, what I would like to know is:
Is it possible to, first, mesh half the surfaces and then duplicate half the nodes using the symmetry plane; After this I would like to map the symmetric nodes I created to the existing half surface that was not meshed so I could apply the pressure load to the full surface and then map it to the existing nodes.
The goal is to have a completely symmetric mesh so that maybe Optistruct has an easier time creating symmetric plies.
Thank you very much!
Gonçalo Pimenta
Answers
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Altair Forum User said:
After running a free sizing optimization the result I get for the plies is not completely symmetric (although I constrained my design variables to be symmetric).
Hi goncalop,
Did you try pattern grouping in the Free Size Panel?. Using this you will get symmetric pattern.
Altair Forum User said:Is it possible to, first, mesh half the surfaces and then duplicate half the nodes using the symmetry plane; After this I would like to map the symmetric nodes I created to the existing half surface that was not meshed so I could apply the pressure load to the full surface and then map it to the existing nodes.
The goal is to have a completely symmetric mesh so that maybe Optistruct has an easier time creating symmetric plies.
Yes you can mesh half the geometry and use reflect panel to reflect the mesh created to other half.
Thank you
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Hi @Premanand Suryavanshi, how are you?
Thank you for your reply!
Altair Forum User said:Did you try pattern grouping in the Free Size Panel?. Using this you will get symmetric pattern.
I used pattern grouping - 1 plane symmetry on the design variables but the result was the one you saw above..
Altair Forum User said:Yes you can mesh half the geometry and use reflect panel to reflect the mesh created to other half
<?xml version="1.0" encoding="UTF-8"?>
So, if I mesh the red surface first and then reflect to 'mesh' the blue surface, will the blue surface be associated with the reflected nodes?
This question because, as mentioned above, I'll need to map the pressure loads to the nodes and I use the surfaces to do this.
The red surface will map the pressure load to the mesh I created with it but, will the blue surface map the pressure load to the reflected nodes?
Hope I was clear and you understand what I'm asking.
Thank you very much!
Gonçalo Pimenta
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Altair Forum User said:
So, if I mesh the red surface first and then reflect to 'mesh' the blue surface, will the blue surface be associated with the reflected nodes?
This question because, as mentioned above, I'll need to map the pressure loads to the nodes and I use the surfaces to do this.
The red surface will map the pressure load to the mesh I created with it but, will the blue surface map the pressure load to the reflected nodes?
Hope I was clear and you understand what I'm asking.
Why don't you try and see.
Thank you
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Altair Forum User said:
Why don't you try and see.
Sorry for the redundant question... I've just tried and it does work.. I must have tried it sometime before and done something wrong..
I'm trying to find a work around for a problem and it's driving me mad.
Sorry for wasting your time!
Thank you for taking the time to answer me!
Gonçalo Pimenta
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No problem. I'm happy to help you. You can get back with your problem anytime.
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Thank you
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I don't know what I did in the morning but I probably pressed reflect twice of something like that. I was building a new model with the symmetric mesh and BC - Loads on Geometry doesn't work. Also, if I try to apply the pressure and then chose, elements by geometry, it also doesn't work..
I first noticed this with the connectors that were acting weird. Then I proceed to test the loads and it definitely doesn't work.. Take a look:
<?xml version="1.0" encoding="UTF-8"?>
<?xml version="1.0" encoding="UTF-8"?>
<?xml version="1.0" encoding="UTF-8"?>
Although the mesh is symmetric, on the side that was originally meshed, the connectors seem to be more numerous and have a mesh with a smaller square.
<?xml version="1.0" encoding="UTF-8"?>
Here, you can see the mesh and the pressure loads applied to the surfaces (the surfaces are hidden). When I map the load, this happens:
<?xml version="1.0" encoding="UTF-8"?>
The side I originally meshed (left) gets the loads on the elements created from the surface. On the right side, the mapping fails..
Do you have any idea how to solve this?
If you need some background on what I'm trying to do, check this post:
It's a little bit extensive so far but every problem I've faced (and am facing) so far is more or less well detailed there.
Thank you for your help!
Gonçalo Pimenta0 -
Hi goncalop,
Please can you share your model.
Please use below FT link to share your model.
https://ftin.india.altair.com:8443/filedrop/~osKE8Q
Thank you
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I just sent you the .hm file I was working on.
If you need anything else, let me know!
Thank you very much,
Gonçalo Pimenta
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Hi,
I got your file. Working on it.
Thank you
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HI @goncalop
You can try transformation tool to reflect elements and loads.
<?xml version="1.0" encoding="UTF-8"?>
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So I apply the loads before reflecting the elements, this way the elements reflected have the loads applied to them too. Am I right?
Also, what about the connectors?
Thanks!
Gonçalo Pimenta
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HI,
Yes, you apply or map the loads on Geometry to elements and reflect both elements and loads. But make sure you select transform loads and right direction to reflect.
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Thanks @Prakash Pagadala!
I will try that this morning.
Do you have any suggestion regarding the connectors (the problem shown above)?
Thank you very much!
Gonçalo Pimenta
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