optimization_with_ANSA.pdf

A N

SA v.13.x

Optimization with A SA

Table of Contents

1. Introduction...................................................................................................................................3

2. The Optimization Task..................................................................................................................3

2.1. The Optimization Task modes ..............................................................................................3

2.2. Defining the Optimization Task .............................................................................................3

2.2.1. Design Variables for Morphing Parameters - Shape Optimization .............................5

2.2.2. Design Variables for ANSA Parameters - Parameter Optimization ............................9

2.2.3. Session commands....................................................................................................14

2.2.4. Script commands - Spotweld Optimization................................................................16

2.2.5. The FE Output File.....................................................................................................19

2.2.6. The Design Variables Input File .................................................................................21

2.3. Checking the Optimization Task ........................................................................................23

2.3.1 Checking the optimization sequence...........................................................................23

2.4. Run the Optimization Task.................................................................................................25

2.4.1. Using current values...................................................................................................25

2.4.2. Using the DV File and FE Output files........................................................................28

2.4.3. The Report Log ..........................................................................................................29

2.5. Connect the Optimization sequence with a parametric optimizer........................................31

2.5.1. Parsing the DV File .....................................................................................................31

2.5.2. Run the Optimization Task..........................................................................................32

2.6. Combined shape and spotweld optimization.......................................................................33

2.7. Using transformations in optimization .................................................................................34

3. Multi-disciplinary optimization .....................................................................................................39

4. Defining a simple DOE................................................................................................................41

5. Using META Post for optimization ..............................................................................................47

5.1. Extracing responses through META Post ...........................................................................47

5.2. Running the META Post session ........................................................................................52

BE A CAE Systems S.A.

A N

SA v.13.x

Optimization with A SA

1. Introduction

In this document is described the capability of ANSA to work as a pre-processor for the set up of

optimization problems. Any tool or functionality which is related to optimization is described here.

The user can follow the document as a tutorial since each section has related small example files.

Alternatively, the document can be used as a User’s Guide. To obtain the example files visit

www.beta-cae.gr and login. Switch to the [Public] directory and go to the folder

. /ansa_v13.0.3/tutorials_and_examples/examples/optimization_examples/.

This document covers the fields of setting up an optimization problem for shape, parameter and

spotwelds, as well as the use of Meta Post for extracting responses.

2. The Optimization Task

The set up of the shape and parameter optimization problem and the coupling of this process with

optimizers can be achieved through the Task Manager of ANSA. The Task Manager is a powerful

tool which can organize and automate the set up of specific pre-processing tasks, like frontal or

side crash, for a given solver. A special task, the Optimization Task is used for the definition of

optimization problems.

2.1. The Optimization Task modes

The Optimization Task can work in two different modes the Definition and the Execution.

The Definition mode

is used to set up all the needed Task Items and actions that will take place to the optimization

sequence. This is the default mode when a new Optimization Task is created.

The Execution mode

runs all the defined Task Items and actions.

The user can switch modes at any time by editing the Optimization Task card. This action is

described in detail in a later section.

2.2. Defining the Optimization Task

In this section a pre-processing sequence will be defined which will be controlled by an optimizer.

This is a sequence of ANSA functions that are executed in specific order. Furthermore, these

functions can be controlled by the design variables of the optimization problem. The optimization

sequence is defined through the Task Manager Tool. This sequence is saved in the ANSA database

when the user saves the database.

BE A CAE Systems S.A.

A SA v.13.x

Optimization with A SA

Open file: hook_01.ansa

Open the above ANSA database using the

FILE>OPEN button.

Use the FILE>TASK ON to open the Task

Manager. To create a new Optimization Task pick

on the Tasks button and select the Optimization

Task from the pull-down menu that appears.

A default Optimization Task is defined which

contains the following Task Items:

1. DV file : design variables input file

2. Design Variable : A design variable

3. FE_Output : Output command for the FE

model.

The right mouse button on a Task Item opens a

pull-down menu with the available options for each

Item.

To define more Design Variable Items, right click on

the Optimization Task and select New>Design

Variable in the pull-down menu that appears.

A new Design Variable Item is added to the Optimization Task.

Each design variable can control a number of Morphing

Parameters, ANSA Parameters, Session Commands or user

Scripts. It is also possible to control any combination of the above

entities.

BE A CAE Systems S.A.

A SA v.13.x

Optimization with A SA

2.2.1. Design Variables for Morphing Parameters - Shape Optimization

The shape of an FE model can be controlled through the Optimization Task. Since the change of the

model shape should be controlled in a parametric way, the Morphing Tool should be used to define

the appropriate Morphing Boxes and Parameters. Then, the defined Morphing Parameters will be

connected to the Optimization Task.

Open file: hook_02.ansa

In this example the shape of the model will be

controlled by two design variables.

The first design variable will control the outer width

of the model as shown at the picture on the left. The

second design variable will control the length of the

sections A, B and C. The design variables will

control the relative Morphing Parameters which

have been already defined.

Section C

Section B

Section A

Outer

Width

At this point delete the first Design variable in order

to create it automatically using an existing morphing

parameter. Right click to the Design Variable Item

and select Delete .

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