continuous vs discrete composites size optimization

Altair Forum User

Hi,

 

I've been doing some composite optimization and i'm having problems going from the continuous size optimization to the discrete size optimization. I read the tutorial and watched the video for the example of the Formula-Student-Monocoque but it hasnt helped me. 

 

So after I run the optimization of the continuous size optimization, I dont know what to open next. In which file are the resultes with the new changed conitous size plys? If I open the FEM file the plys are the same as before. 

 

Even in the tutorial files for the monocoque the file: '06_size_konti_complete' is the same as '07_size_discrete' ( apart from the changed TMANUF). So i dont understand why to do the continuous size optimization at all if they dont use the results.

 

Do I need to change some control cards settings maybe, to get a file with the results?

 

I hope you understand my porblem,

Best regards

 

Diego

Altair Forum User

I think I found a solution, but please correct me if im wrong!

 

In the tutorial it says to import the .desvar file after the continuous size optimization. Which didnt contain the new ply thikness and therefore the modell remained the same. I tried importing the .prop file and this does contain the optimized continuous ply thikness so now i can work with the continuous size optimization results. 

 

Please confirm and if it is like I say let me know so I can inform someone to correct the tutorial.

 

cheers

Altair Forum User

Hi,

 

Yes, its the .prop file which contains new thickness values.

Altair Forum User

Thank you for your reply Prakash,

 

I still have one question regarding this tutorial, maybe aou can help me. Why are they defining before the continuous size optimization a static stress response and constraint? And what does major principal and both surfaces mean? wouldnt it make more sense to define a composite stress response?

 

thanks in advance,

Diego

Rahul Rajan_21763

PFA new feature on OS 14.0 for optimization.

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

Altair Forum User

Thanky for your reply Rahul,

 

does this mean that using a static stress with composites is wrong?

 

I tried making a failure response of composite elements and a constraint for maximum failure, but I get some error saying that failure response is not allowed in optimization. Could it be that the Student Version doesnt support failure response and constraint?

Altair Forum User

Altair Forum User said:

I tried making a failure response of composite elements and a constraint for maximum failure, but I get some error saying that failure response is not allowed in optimization. Could it be that the Student Version doesnt support failure response and constraint?

Hi Diegoz,

Can you paste the entire error message here?

 

What is the failure response type have you used?

 

Strains are calculates using the compliance and stress matrix in the fiber axis and the same are transformed to angled plies using transformation equation.

Altair Forum User

I created a composite failure response for all plies and the created a constraint with a max. upper bound of 1.

Here is the error I get:

 

 A fatal error has been detected during input processing:

  *** ERROR # 1807 ***
  Composite failure responses are applied to ply 1 which
  belongs to a topology or free-size domain.