Optistruct Convergence Settings

exx077

Hello,

 

I am running a topology optimisation using Optistruct. The results I am getting for a standard min. compliance, constrained volume fraction run without any manufacturing constraints are invalid. The simulation runs but the results do not show any clear structural members but mostly very low density material.

However, when I use minimum member size control, extrusion constraints and change the discrete value the results achieved are valid (show structural members).

 

Is there a way to chance the minimum convergence parameters to encourage the solution to find a valid structure for on optimisation without manufacturing constraints.

 

Thank you in advance

Altair Forum User

Hi @exx077

 

Usually, results without manufacturing constraints are best results but not manufacturable. 

 

Did you try to change the ISO value in HyperView?

 

Is it possible to share the model file?

exx077

Hi @Prakash Pagadala,

 

I have had a look at the iso result on Hyperview. This is how I can tell there is lots of low density material (<0.05). There are only 8 iterations, which is what makes me think that there may be insufficient convergence.

 

Density>0.05 for VF=0.05 (left) and 0.075 (right)

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

 

Density>0.1 for VF=0.05 (left) and 0.075 (right)

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

 

HM file:

 

 

des.H3D file:

 

 

 

Thank you

Altair Forum User

Hi,

 

PFA results 

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

exx077

Hi @Prakash Pagadala,

 

Wow, these results look great!

However, I do not understand what they are showing.

 

Does PFA stand for Progressive Failure Analysis?

If so, do the regions or high density show where probability of failure is highest?

 

Thanks

Altair Forum User

PFA( Please find attached results)

 

The results show optimal material layout. Red being the highest material density. 

exx077

@Prakash Pagadala,

 

I see, thank you.

 

What optimisation parameters have you used?

The square panel regions are really impressive.

 

Thanks

Altair Forum User

I will share the model with you

exx077

Great, thanks again @Prakash Pagadala