Composite optimization of a laminate with full-surface plys

Altair Forum User

Hello,

 

I built a Kiteboard Model (sandwich structure) with shape parameters for easy changeable designs. In a last step I want to run a composite optimization in which the Board/ laminate will be optimized to minimize the volume/mass.

 

Therefore I tried to use the 3 phases composite optimization. Because later on I want to change the used plys in an easy way by activate/ deactivate them in the created laminate.

 

I know that there is another optimization opportunity for size- optimization. But there you have to create design variables for each ply. So if I choose other plys for the optimization (e.g. because of other materials used) I have to define everything new.

 

 

Now my questions are:

 

Is there any possibility at the 3 phases composite optimization to define that each ply would be created over the whole surface of the Board? So that these small pieces of single plys, created during the free size optimization, could be avoided in the end.

 

Or is there any other opportunity to use the created laminate, not the plys in herself, for the optimization?

 

 

Best regards

Till

Altair Forum User

Hi Till,

 

Maybe you can use OSSmooth to remove small patches created during the optimization.

 

Please give it a try and let us know if you are happy with the results.

Altair Forum User

Hi Prakash,

thanks for your response.

 

I tried many cases without any good results.

 

My approach is:

- running Free Size optimization

- start Ossmooth from Post- subpanel

- select the Free-Size *.fem file

- select option: PLY Shape

- select smooth interation from 1 till 20 (in different cases)

- as small region I tried area ratio from 0 till 1 (in different cases) also elem count from 1 till 10000

- split disconnected checked and unchecked

- create geometry = checked

 

In case of split disconnected is checked OSSmooth creates more than 20000 plys.

If it is unchecked in most cases only 3 Plys were created by OSSmooth. But all the Plys are placed in the top-laminate of the Board. The bottom-laminate is empty. The result is Error # 1901: 'Stack must have eighter a list of Plys or substacking data' appears while running a check for size- optimization.

 

I also tried to create 2 Design Variables (1x top, 1 bottom) and define minimum ply thickness for each in the Free-Size optimization. But OSSmooth also placed the plys only in top-laminate.

 

At the moment the only goodness in it is that all created Plys were created over the full-surface of the top without the small Ply patches.

 

 

Best regards

Till

Altair Forum User

Hi Till,

I can reproduce the same at my end. I will check and get back to you soon.

Altair Forum User

You can use the Ply Geometry Smoothening Tool in the aerospace Toolbar:

 

1.      Import  the Size Optimization Model into HM

2.      Run the tool and define the small regions which should be deleted either via area or element count

3.      The increased number of plies is possible due to the  Split disconnected ply into different plies function

 

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