OSSMOTH problem

Altair Forum User

Hey guys!

 

I made a tutorial of composite optimization which contains a ply smoothing steps. The name of the tutorial: OS-T: 3400 Design an Open Hole Tension (OHT).

 

The model setup was the same and I got the same result for linear static analysis just like in the tutorial. The optmization went well, I got the same result as you can see on the attached picture. In the tutorial the name of the plies are different because I use the version 2017.2 . I have 2 plies which contain the same element like in the tutorial.

<?xml version="1.0" encoding="UTF-8"?>

After free-size optimization I made the next step: OSSMOTH. It gave me some funny result as you can see on the pictures. You can see the settings are the same and the results still different.

<?xml version="1.0" encoding="UTF-8"?>

 

On the 3rd picture you can see the OSSMOTHING result from the tutorial. You can see that the settings are the same but the results are very different.

 

<?xml version="1.0" encoding="UTF-8"?>

 

Could someone explain why I got so different result?

 

Thanks for your answer in advance!

 

Best regards,

Imre

Altair Forum User

Hi @Imre

 

Can you share the freezie fem file, please?

 

Please use the file transfer link in my signature to share the model file

Altair Forum User

Hi Pagadala!

 

Of course I can share the file. I send it via FileTransferLink.

Altair Forum User

Got it!!

 

thank you

Altair Forum User

Hi @Imre

 

I see 22 plies after freesize. This could be because of the splitting of disconnected plies. 

 

Please add Control cards>> DEBUG,FS-SPLIT , 0 and check if this helps.

<?xml version="1.0" encoding="UTF-8"?>

Altair Forum User

Hi Prakash!

 

I add control cards DEBUG, FS-SPLIT. After the free-size I got 16 plies just like in the tutorials, and the shape and thickness of the plies were the same.

But OSSMOOTH algorithm seems a little bit problematic as you can see on the picture.

<?xml version="1.0" encoding="UTF-8"?>

 

I sent you the updated .fem file via your file transfer page. Could you run an OSSMOOTH with the same settings to see what kind of results you got?

Thank you for your help!

Altair Forum User

@Imre

 

I think the problem is with the OSSmooth module. I will report this to the Development team.

 

You can try Geometry ply smoothing which is available in Aerospace profile. That gave close results but not exactly the same. 

Altair Forum User

Hi Prakash!

 

Thanks for your help! With Geometry ply smoothing I was able to get something similar. I think I have just to make some magic with the settings (iteration steps, area ratio etc.).

I read a former topic about the ply-shape smoothing where you wrote that 'Area ratio: local region area / total design area (real value between 0.0 and 1.0. Default=0.01)'.
 

Are the area ratio calculation method the same in OSSMOOTH and in the Geometry Ply Smoothing (in Aerospace menu)?

Ps.: where can I check such tip&tricks that you wrote me before about the debug control card? I did not find the debug card in the HM, HW, or Optistruct help. In the help of control cards that is all about debug card: 'Some special or custom features can be accessed through the use of 'debug, <string>, <real>' statements.', which is not so much help for me.

 

Thanks for your help in advance!

 

Imre

https://community.altair.com/community?id=community_question&sys_id=7276083a1b2bd0908017dc61ec4bcb5b

 

Altair Forum User

Hi @Imre

 

The tip which I provided is under development and this will be a part of GUI soon. 

 

We usually create tip and trick documents and available on http://altairuniversity.com website

Altair Forum User

Hi Prakash!

 

Thanks for all of your help!
I am aware of  tip&trick topic on altairuniversity website. I like the support and the development of the Altair, thanks for all!

 

Best regards,

Imre