DRESP3

Altair Forum User

Hi

 

Has anyone done much with DRESP3 and accessing external functions?

 

I am trying to use HyperMath to aggregate constraints in a size optimisation problem.  I can get it to work if all my responses are of the same type (e.g DRESP1 - Stress), but if I try to combine a displacement (still DRESP1) constraint with a stress constraint I get an error

 

'Number of responses in DRESP3 inconsistent'

 

I have tried normalising both responses using equations, so now both responses are DRESP2, but I get the same error which occurs before completion of check.

 

Any thoughts how I can get around this?  or what may be going on?

 

Cheers

 

 

Altair Forum User

Hi Erica,

 

I know this dates from quite a while, but is there any chance you've found a solution to your problem ? I am facing the exact same issue with Optistruct at the moment as I am trying to have a Stress-based aggregation function as my optimization response, but all of my efforts with DRESP2 have been fruitless so far. I am trying to code an external function using DRESP3 at the moment but I am not really sure how to do that, given that my input response is the static stress >  Von Mises one (which is a vector of the stress for each of the 100+ elements in the element set my response is defined on). I would really appreciate it if you could tell me of any workaround you've used to solve your problem.

 

Thanks in advance