visualization sudden change when adding CFK plies

Altair Forum User

Hi!

 

I have a problem with a sandwich panel simulation. When modelling an aramid core + 9 CFK plies in each side everything looks good an results are fine. However, when adding 1 or more plies, results are wrong. The sandwich suddenly moves out of the screen and displacement values are way too high comparing with the previous. I attach the file below.

 

Thanks in advance!

 

Altair Forum User

HI,

 

Thank you for sharing the file. 

 

Can you point me to the new ply added on the laminate?

 

Can you check if the model is under constrained?

Altair Forum User

Hi Prakash,

The plies that make the model fail are tenth and above. In the file I attached there are twelve plies, but if you delete plies 11 and 12 the same problem appears.

I don't know if there is any underconstrained checking tool but I don't think it is because it works fine when reducing the number of plies.

One thing I forgot to tell you is that I duplicated the plies instead of creating new ones; however, I don't see why that could be a problem.

Thank you again for your attention.

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Altair Forum User

OK,

 

I will check and I will get back to you. 

Altair Forum User

Hi,

 

I am able to reproduce the same. But if I constrain in all direction I see results. 

 

Let me check with experts about this and I will share their feedback. 

 

Altair Forum User

Okey! 

I actually need only dof3 to be restricted because it's a 3 point bending simulation so I'll wait for the experts answer.

Thanks for your time!

Altair Forum User

HI,

 

I changed the orientation of the last three plies and I see reasonable displacements. 

 

Can you please let me know what the analysis is about and the objective of analysis?

Altair Forum User

Hi Prakash,

sorry for the late response. The simulation is a 3Point Bending test to estimate the number of plies of a FSAE monocoque.

I need to add and remove plies in order to optimize rigidity and weight.

Thanks

Altair Forum User

Hi,

 

OK let me test on a sample coupon and I will get back you soon,