Problem Optimization

Altair Forum User

Hello everybody,

I'm trying to do a composite optimization following the tutorial that described a monocoque FSAE optimization; I made the first step (free size optimization) but when I try to edit the ply shape for manufacturability and I try to start the second optimization, I have an error:

 

 A fatal error has been detected during input processing:

  *** See next message about line 31 from file:
      C:/Users/Salvatore/Desktop/Altair ottimizzazione manuale/Ottimizzazione/Ottimizzazione con DOF
   'DESOBJ(MIN)=6'

  *** ERROR # 1041 *** in the input data:
  Card DESOBJ conflicting with previous DESOBJ, MINMAX, or MAXMIN data.

 

I noticed that after the first optimization are created automatically other objectives, other otpimization control, response and constrains; maybe they could be the cause of this error?

Thanks 

 

Altair Forum User

Hi Salvinho,

 

I think there are two objective functions. Can you please check this?

Altair Forum User

Hi Prakash,

I resolved the problem: the second objective resulted because I loaded model and solver deck.

I have another question...

There is a method to optimize a monocoque with honeycomb core? I would to treat honeycomb as ply; it's possible?

Altair Forum User

Yes, you can treat the core as a ply using shell elements.

Altair Forum User

Thanks Prakash, but How  can I do to assign honeycomb material to shell elements?

Rahul Rajan_21763

Hi,

For linear analysis honeycomb modelling as in core for composite analysis is usually modelled with SOLID elements with equivalent isotropic properties. The ply’s/laminae which are the face sheets on either side of the core are modelled with Shell elements (PCOMP/PCOMPG/PCOMPP) with orthotropic material property.

 

Regards

Rahul R

Altair Forum User

Thanks for reply :-)