Problem of size optimization's desvar

Altair Forum User

@Prakash Pagadala I got it ! really thanks

 

but why we set value at neg = -1 and pos = 1

 

why no there is be any value

Altair Forum User

Hi,

 

I left it default (or maybe forgot to update) /emoticons/default_smile.png' srcset='/emoticons/smile@2x.png 2x' title=':)' width='20'> 

Altair Forum User

@Prakash Pagadala 

 

Ok Really thanks to you 

 

so at the future I just set it yo -1 and 1

 

very thanks to you !

Altair Forum User

Hi,

 

For example, you have an optimization problem such as min(max(stresses)) and you also want to keep the stress value smaller than 200MPa. Then you can define 200 as your reference number instead of 1.  If you don’t have a bound on the response, then you can simply keep it as 1. 


If you have a setup as min(max(displacement)) and the displacements are negative and you would like to normalize the multi-responses with their bounds, then you will need to input the negative value (negative bound) as the reference value. It totally depends on the bounds.

Altair Forum User

HI @Prakash Pagadala

 

But at here I do the stress constrain and I set pos=1

 

it means the stress will under 1MPa?

 

At the result it stress is over

 

Altair Forum User

No,

 

The solver will minimize the maximum of the response. Please go through the document I shared earlier which explains how reference values are used. 

Altair Forum User

@Prakash Pagadala

 

I got it, you said the value if we set 200 is the stress constraint 200 MPa.

 

And if I set 1 means I didn't have any constraint at my response.