Shuffling phase in composite optimisation of a formula student monocoque

Altair Forum User

Hi,

 

I am currently trying to do composite optimisation of a carbon fibre sandwich structure monocoque. I have been following the  'composite optimisation of a formula student monocoque' tutorial on the Altair university training website and am up to the shuffling stage however am not getting any results and getting this message:

 

 *** WARNING # 1569

 for element id = -70001.

 Thickness is zero for this composite. This will produce meaningless stress

 results and may cause singularity of the global stiffness matrix.

  

 *** WARNING # 1569

 for element id = -70002.

 Thickness is zero for this composite. This will produce meaningless stress

 results and may cause singularity of the global stiffness matrix.

  

 *** WARNING # 1569

 for element id = -70003.

 Thickness is zero for this composite. This will produce meaningless stress

 results and may cause singularity of the global stiffness matrix.

  

 *** WARNING # 1569

 for element id = -70004.

 Thickness is zero for this composite. This will produce meaningless stress

 results and may cause singularity of the global stiffness matrix.

  

 *** WARNING # 1569

 for element id = -70005.

 Thickness is zero for this composite. This will produce meaningless stress

 results and may cause singularity of the global stiffness matrix.

  

 *** WARNING # 1569

 for element id = -70006.

 Thickness is zero for this composite. This will produce meaningless stress

 results and may cause singularity of the global stiffness matrix.

  

 *** WARNING # 1569

 for element id = -70007.

 Thickness is zero for this composite. This will produce meaningless stress

 results and may cause singularity of the global stiffness matrix.

  

 *** WARNING # 1569

 for element id = -70008.

 Thickness is zero for this composite. This will produce meaningless stress

 results and may cause singularity of the global stiffness matrix.

  

 *** WARNING # 1569

 for element id = -70009.

 Thickness is zero for this composite. This will produce meaningless stress

 results and may cause singularity of the global stiffness matrix.

  

 *** WARNING # 1569

 for element id = -70010.

 Thickness is zero for this composite. This will produce meaningless stress

 results and may cause singularity of the global stiffness matrix.

  

 *** More of WARNING messages # 1569 were suppressed...

  

 thanks in advance for any advice.

 

Toby

Rahul_P1

You can ignore this warning message, the lack of results may be due to a different modelling problem. 

Altair Forum User

thanks for your reply, the only other warning/error I'm getting is this:

*** WARNING 1932:     PROD  ID   11 is not referenced.

Any ideas?

 

On another note, going back to the free sizing phase -  the optimisation doesnt do anything if my laminate has plies any thinner than 2mm thickness resulting in a much heavier chassis than the one I'm trying to optimise even after free sizing. IS there away round this?  

 

Thanks