Selection of Best Optimization Algorithm

Nahid3007

Hello community,

 

I got a little bit confused while reading the OptiStruct 2017 User’s Guide.

 

There I found that OptiStruct selects automatically the best optimization algorithm. Five items have been listed there (page 10-11):

- Optimality criteria method

- Convex approximation method

- Method of feasible directions

- Sequential quadratic programming

- Advanced approximations .

 

My question is: Does OptiStruct still selects the Optimality criteria method automatically? And for which type of optimization? There is no information about it in the User’s Guide or Reference Guide.

 

I want to optimize the topology of the 2 dimensional MMB-Beam (see atteched figure). My objective is to minimize compliance subjected to a volume fraction constraint.

 

I found that for my type of problem I shoud use 'OPTMETH=DUAL' since I have a large number of design variable and only one constraint.

 

So I cannot choose the Optimality criteria method in topology optimization?

 

Many thanks in advance

Nahid

 

 

 

 

 

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Altair Forum User

Hi,

 

The default optimization algorithm is known as the Method of Feasible Directions (MFD),

 

From OptiStruct help:

The DUAL algorithm should be used for concept-level optimization (Topology, free-size, and Topography) since such problems typically involve a very large number of design variables.