Problems with Free Size optimization constraints and pattern grouping

Altair Forum User

Hello!

 

I'm having troubles setting up a free size optimization, although I've done it successfully before. 

 

First of all, I have a problem with the core thickness: I have defined core thickness (tried both by ply and by angle), but I still get the following error:

 

Error #859

The following constraint on DSIZE may be incorrectly defined because it does not involve any designaable (or existent) plies in some areas of the laminate. This may cause constraint violation throughout the optimization process

CONST for PLY 3 

 

The same happens for ply 2.

 

I also got another error on the way:

 

Pattern grouping or pattern repetition is requested on DSIZE card 1 but referenced PCOMP properties do not have the same number of plies. Therefore, pattern grouping and pattern recognition will be ignored.

 

Could you please ry to help me fix the errors? I checked the ply definition and as fas as I can see, it looks fine. I defined the plies using sets. 

 

Thanks in advance.

 

Question to the admins: do you see my attached files or do I need to insert the model explicitly in this thread?

Unable to find an attachment - read this blog

Altair Forum User

Hi @John Doe

 

Can you share the file using file transfer link in my signature below?

Altair Forum User

Done. 

Altair Forum User

Hi John,

 

Thank you for sharing the file. I ran your model in 14.0 and I see the error you specified as a warning message instead of error. 

 

But, Still I need to see why a warning message is shown when the ply is a part of design variable.

Altair Forum User

Hi Prakash,

 

thank you for the reply. 

 

On several occasions the simulation ran despite the error (or maybe it just showed it as a warning), but then the results were meaningless - everything had constant thickness, including the other plies. 

 

I hope you can find the reason for this problem.

 

Thank you in advance.

Altair Forum User

Hello Prakash,

 

have you managed to find the reason for the error?

 

Greetings,

Galin

Altair Forum User

Hi @John Doe

 

I changed few Params and submitted the run at my end to check the results. It is taking long to complete. Once the results are out I will share my feedback.

Altair Forum User

Hi Galin,

 

So I am still investigating the warning message, but in the laminate thickness constraint make sure you include the thickness of plies which are constrained as CONST on DSIZE.

 

I think this is what causing the problem. Meanwhile I wrote to experts about the warning and awaiting their response.