topology optimization Iteration 0 parameters

Altair Forum User

hi,

 

I was going through OS-2095: Frequency Response Optimization of a Rectangular Plate tutorial problem, I was not getting how the Iteration 0 is initiating, I mean software has to assign parameters to problem, I would like to know what the parameters are assigning by software for Iteration 0 ?

 

I was asking about Iteration 0 , because I tried assigning parameters for density & thickness values like mentioned below

 

I opened the ” _des.h3d ” file in hyperview, I checked the iteration 0 results for element thicknesses & element densities , i got the uniform values of 0 .915 & 0.9 respectively from contour plots. I given parameters i.e., thickness of 0.915mm & density = (0.9 * original density) to the problem . submitted for solution. I was getting results kind of similar to the iteration 0 results from optimization problem, but not matching. hence I would like to know about iteration parameters more clearly & how the problem is being setup. are my understandings correct while assigning parameters?

 

I would also like to know, how to calculate standardized density value , that comes in element density contour plot ? Is it the % of density value ( original density ) that was assigned to the design elements?

 

I want to understand clearly the .out file of optimization solution, if any document related to this , please let me know / forward to my e-mail ID ?

 

out file of the problem is attached please find it

 

Your feedback is highly appreciated,

 

Thank you!!

Rahul_P1

srinivasGM

 

In topology optimization, The SIMP method (Solid Isotropic Material with Penalty) is used in OptiStruct. In the SIMP method, a pseudo material density is the design variable, and hence it is often called density method as well. The material density varies continuously between 0 and 1., with 0 representing void state and 1 solid state.

 

See  Altair OptiStruct > User's Guide > Design Optimization > Topology Optimization:

Design Variables for Topology Optimization

 

 In the first iteration of the topology optimization, the density of the design space is less than 1.0, unless you have expressly set the MATINIT value, defined on the DOPTPRM bulk data entry, to 1.0.

 

For more details about the out file See

Altair OptiStruct > Reference Guide > Output Data > List of Files Created by OptiStruct (Alphabetical): .out file