ERROR # 1805 / Optimization Constraint aplied on -> DRESP1->RMS_Stress->SigmaXX during topology optimization of part represneted by solid elements

Imrich

Hello, 

problem I am solving is:

Two Subcases are defined: 

1. Unit load FRF case that is needed for RANDOM case

2. RANDOM case

description of cases: The main point is that I am loading plate modeled with 3D solid elements by random force that have defined force spectral density with Frms around 50 Newton.

 

 

Next I wanted to use topology optimization setup:

Design Variable: Topology design variable aplied to property "property1" which is related to                                   elements in design region

Responses: 1. DRESP1= Mass (total)

                 2. DRESP1= RMS STRESS SXX aplied to property "property1" which is related to                                              elements in design region; I also defined RANDPS that is related to my                                        random  case

Constraints: I used dconstraint for constraining RMS_STRESS SXX where upper limit is choosed 300 MPa.

OBJECTIVE: Min (Mass response)

 

Description: So basically I wanted to Minimize Mass of the plate by topology optimization while keeping RMS STRESS SXX in elements of the plate under 300 MPa (Initial state had lower maximal RMS STRESS SXX).

 

What happend when i tried to solve this problem:

I get this error in .out file:

*** ERROR # 1805 ***
Stress/strain/force responses are applied to element 24762 which
belongs to a topology or free-size domain.

This error occurs in module "dppdrv1".

 

 

I attach .opt and .fem file if it helps.

 

I think this prolem should work, but I don't know what to do.

I would appreciate your help.

Thank you.

 

 

Adriano_Koga

Hi,

 

For topology optimization of Random response, you cannot use the RMS stress constraint in the design region (only non-design area).

regular stress constraints for static is available, but not RMS.

Even in newer versions this is still not allowed.

 

you would probably need to change your strategy here.

Adriano_Koga

Hi,

 

For topology optimization of Random response, you cannot use the RMS stress constraint in the design region (only non-design area).

regular stress constraints for static is available, but not RMS.

Even in newer versions this is still not allowed.

 

you would probably need to change your strategy here.

Adriano_Koga

Adriano A. Koga_21884 said:

Hi,

 

For topology optimization of Random response, you cannot use the RMS stress constraint in the design region (only non-design area).

regular stress constraints for static is available, but not RMS.

Even in newer versions this is still not allowed.

 

you would probably need to change your strategy here.