Optimization Study

Overview

First, it is necessary to define variables and responses. Among the responses, one will be defined as the objective function. The others can be used in limiting constraints.

The goal of an optimization study is to find the solution of a problem of the following type:

Minimize (Objective Function)

Subject to:

Inequality Constraint 1 < Limit 1

Inequality Constraint 2 < Limit 2

...

Equality Constraint 1 = Value 1

Equality Constraint 2 = Value 2

With:

minimum1 < design variable 1 < maximum1

minimum2 < design variable 2 < maximum2

...

Design Variables and Responses

•	Variables are model characteristics which vary during the analysis.

•	Responses are results which are extracted at the end of each computation and stored for post-processing.

•	The goal of a parametric study is to discover the influence of variables modifications on the model responses.

To define variables and responses:

1.	From the Menu Bar, select Process, then Study, then Optimization, then Edit Parameters.

A new notebook page appears.

2.	Go to the Variables or Responses page.

RADIOSS Computational Options

Just after the variables and responses are defined, it is necessary to also define the version of RADIOSS to be used, the number of processors, and how the computations should be submitted.

To define the computational options:

1.	From the Menu Bar, select Process, then Study, then Optimization, then RADIOSS Computational Options.

The following window appears:

define_radioss_options

2.	Select an Execution Mode.

3.	Select the RADIOSS version to use.

4.	Enter the Number of Processors to use.

5.	Click the Ok button.

Create New Task or Open Existing Task

Performing a task consists of defining an optimization problem and solving it. Before creating a new task, design variables and responses on the model should have been defined. Also, the RADIOSS computational options should have been defined.

Create a new optimization task

1.	From the Menu Bar of HyperCrash, select Process, then Study, then Optimization, then New Optimization Study.

The following window appears.

newOptStudy

2.	Enter a Task Name and click Ok.

A directory named MOPT_TASK_D00RootName_TaskName is created, and all the necessary files are copied into it. The DSS / MOPT module with which the problem definition, resolution and post-processing are going to be performed is then run.

The next step is the definition of an optimization problem.