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<a name = "hj-top"> </a><table class = "table1" id = "table11"><tr><td><table class = "DocHeader"><tr><td class = "DocHeader1" colspan = "2"><h1>The Optimization Task</h1></td></tr><tr><td class = "DocHeader4" colspan = "2"/></tr><tr><td class = "DocHeader3" colspan = "2"><table class = "DocThemeIntro" id = "table12"><tr><td class = "Intro1Only"><p class = "header"><p class = "abstract">
<span class = "shortdesc">An optimization task always consists of the same basic elements:
design area, objective function and eventually also constraints. This
chapter explains the standard procedure for creation of an optimization
task.</span>

</p>
<p>This page discusses: </p><ul><li><a href = "#tso-c-usr-shape-optTaskOvw__tso-c-usr-shape-optTask-analysisMod" id = "toc_rg" title = "">Analysis Model</a></li><li><a href = "#tso-c-usr-shape-optTaskOvw__tso-c-usr-shape-optTask-desArea" id = "toc_rg" title = "">Design Area</a></li><li><a href = "#tso-c-usr-shape-optTaskOvw__tso-c-usr-shape-optTask-objFunc" id = "toc_rg" title = "">Objective function</a></li><li><a href = "#tso-c-usr-shape-optTaskOvw__tso-c-usr-shape-optTask-constr" id = "toc_rg" title = "">Constraint</a></li><li><a href = "#tso-c-usr-shape-optTaskOvw__tso-c-usr-shape-optTask-optTask" id = "toc_rg" title = "">Optimization Task</a></li><li><a href = "#tso-c-usr-shape-optTaskOvw__tso-c-usr-shape-optTask-stopCond" id = "toc_rg" title = "">Stop Condition</a></li><li><a href = "#tso-c-usr-shape-optTaskOvw__tso-c-usr-shape-optTask-checkRun" id = "toc_rg" title = "">Check Run</a></li><li><a href = "#tso-c-usr-shape-optTaskOvw__tso-c-usr-shape-optTask-compl" id = "toc_rg" title = "">Completion</a></li></ul>
</p></td></tr></table></td></tr></table>




<div class = "body conbody">
<p>The following describes the general procedure for the definition of
an optimization task. These procedures are supported by the command tree in 
<span class = "ph">Tosca Structure.pre</span>
screen of <span class = "ph">Tosca Structure.gui</span>
(GUI). </p>
<div class = "section" id = "tso-c-usr-shape-optTaskOvw__tso-c-usr-shape-optTask-analysisMod"><h2 class = "title sectiontitle">Analysis Model</h2>

<ul class = "ul">
<li class = "li"><span class = "ph">Question: </span> Which file(s) contains the FE-model for the optimization?

</li>
<li class = "li"><span class = "ph">Procedure: </span> Link file(s) to optimization task.<ul class = "ul">
  
<li class = "li"><p>In GUI: Select <span class = "ph menucascade"><span class = "ph uicontrol">Command</span><abbr title = "and then"> &gt; </abbr><span class = "ph uicontrol">FEM_INPUT</span></span>  and choose your model file.</p></li>
</ul></li></ul>
</div>

<div class = "section" id = "tso-c-usr-shape-optTaskOvw__tso-c-usr-shape-optTask-desArea"><p><map name = "FPMap1"><area href = "#hj-top" title = "Back to Top" shape = "rect" coords = "416, 0, 435, 10"/></map><span class = "itemsprite"/></p><h2 class = "title sectiontitle">Design Area</h2>

<ul class = "ul">
<li class = "li"><span class = "ph">Question: </span>Which surface area of the FE model should be selected for shape modifications?  
</li>
<li class = "li"><span class = "ph">Procedure:</span> Assign node group with surface nodes to design area.<ul class = "ul">

<li class = "li"><p>In GUI:  Choose or define the node group with
the surface nodes of the selected design area <span class = "ph uicontrol">GROUP_DEF</span> Command and define the design variables <span class = "ph uicontrol">DV_SHAPE</span>.</p></li> 
</ul></li><li class = "li"><span class = "ph">Question:</span> Which area of the model should be selected for
smoothing of the FE mesh?  
</li><li class = "li"><span class = "ph">Procedure:</span> Assign element group to
<span class = "ph uicontrol">MESH_SMOOTH</span> area.<ul class = "ul">

<li class = "li"><p>In GUI: Choose or
define the element group defining the mesh smoothing area (<span class = "ph uicontrol">GROUP_DEF</span>) and define the mesh smoothing (<span class = "ph uicontrol">MESH_SMOOTH</span>).</p></li> 
</ul></li>
<li class = "li"><span class = "ph">Question:</span> Are there nodes in the design area or in the mesh
smoothing area that are subject to certain restrictions? How can these
restrictions be described?
</li><li class = "li"><span class = "ph">Procedure:</span> Define design variable
constraints for node group.<ul class = "ul">

<li class = "li"><p>In GUI:
Choose or define node groups with common restrictions (<span class = "ph uicontrol">GROUP_DEF</span>).
Define the restrictions using <span class = "ph uicontrol">LINK_SHAPE</span> and <span class = "ph uicontrol">DVCON_SHAPE</span>.</p></li> 
</ul></li>
</ul>
</div>

<div class = "section" id = "tso-c-usr-shape-optTaskOvw__tso-c-usr-shape-optTask-objFunc"><p><map name = "FPMap1"><area href = "#hj-top" title = "Back to Top" shape = "rect" coords = "416, 0, 435, 10"/></map><span class = "itemsprite"/></p><h2 class = "title sectiontitle">Objective function</h2>

<ul class = "ul">
<li class = "li"><span class = "ph">Question:</span> Which terms describe the values to be optimized?
Should these values be minimized or maximized or otherwise combined?
</li>
<li class = "li"> <span class = "ph">Procedure:</span>
Choose terms for optimization (design responses) and target.<ul class = "ul">

<li class = "li"><p>In GUI: Define the design response (<span class = "ph uicontrol">DRESP</span>)
and assign it to the objective function (<span class = "ph uicontrol">OBJ_FUNC</span>).</p></li> 
</ul></li></ul>
</div>

<div class = "section" id = "tso-c-usr-shape-optTaskOvw__tso-c-usr-shape-optTask-constr"><p><map name = "FPMap1"><area href = "#hj-top" title = "Back to Top" shape = "rect" coords = "416, 0, 435, 10"/></map><span class = "itemsprite"/></p><h2 class = "title sectiontitle">Constraint</h2>

<ul class = "ul">
<li class = "li"><span class = "ph">Question:</span> Which design response describes the constraint? Which
value should the constraint have? 
</li>
<li class = "li"><span class = "ph">Procedure:</span> Choose term for
constraint and set target value or upper/lower boundary.<ul class = "ul">

<li class = "li"><p>In GUI:  Define the design response (<span class = "ph uicontrol">DRESP</span>)
and assign it to the constraint (<span class = "ph uicontrol">CONSTRAINT</span>).</p></li> 
</ul></li></ul>
</div>

<div class = "section" id = "tso-c-usr-shape-optTaskOvw__tso-c-usr-shape-optTask-optTask"><p><map name = "FPMap1"><area href = "#hj-top" title = "Back to Top" shape = "rect" coords = "416, 0, 435, 10"/></map><span class = "itemsprite"/></p><h2 class = "title sectiontitle">Optimization Task</h2>

<ul class = "ul">
<li class = "li"><span class = "ph">Question:</span> Are all command definitions listed above complete
and ready for the optimization job? 
</li>
<li class = "li"><span class = "ph">Procedure:</span> If necessary
complete any additional required definitions and prepare the optimization
job.<ul class = "ul">

<li class = "li"><p>In GUI: Reference all definitions above in <span class = "ph uicontrol">OPTIMIZE</span>.</p> </li></ul></li></ul>
</div>

<div class = "section" id = "tso-c-usr-shape-optTaskOvw__tso-c-usr-shape-optTask-stopCond"><p><map name = "FPMap1"><area href = "#hj-top" title = "Back to Top" shape = "rect" coords = "416, 0, 435, 10"/></map><span class = "itemsprite"/></p><h2 class = "title sectiontitle">Stop Condition</h2>

<ul class = "ul">
<li class = "li"><span class = "ph">Question:</span> Should the optimization stop after a number of iterations
(or certain other conditions)? 
</li>
<li class = "li"><span class = "ph">Procedure:</span> Define a stop condition.<ul class = "ul">

<li class = "li"><p>In GUI: Select <span class = "ph menucascade"><span class = "ph uicontrol">Command</span><abbr title = "and then"> &gt; </abbr><span class = "ph uicontrol">STOP</span></span>.</p></li> 
</ul></li></ul>
</div>

<div class = "section" id = "tso-c-usr-shape-optTaskOvw__tso-c-usr-shape-optTask-checkRun"><p><map name = "FPMap1"><area href = "#hj-top" title = "Back to Top" shape = "rect" coords = "416, 0, 435, 10"/></map><span class = "itemsprite"/></p><h2 class = "title sectiontitle">Check Run</h2>

<ul class = "ul">
<li class = "li"><span class = "ph">Question:</span> Would prior testing of the restriction definitions
be useful? 
</li>
<li class = "li"><span class = "ph">Procedure:</span> Apply test displacements.<ul class = "ul">
 
<li class = "li"><p>In GUI: Select <span class = "ph menucascade"><span class = "ph uicontrol">Command</span><abbr title = "and then"> &gt; </abbr><span class = "ph uicontrol">  TEST_SHAPE</span></span>.</p></li> 
</ul></li></ul>
</div>

<div class = "section" id = "tso-c-usr-shape-optTaskOvw__tso-c-usr-shape-optTask-compl"><p><map name = "FPMap1"><area href = "#hj-top" title = "Back to Top" shape = "rect" coords = "416, 0, 435, 10"/></map><span class = "itemsprite"/></p><h2 class = "title sectiontitle">Completion</h2>

<ul class = "ul">
<li class = "li"><span class = "ph">Question</span>: Has all the required data been specified?
</li>
<li class = "li"> <span class = "ph">Procedure:</span>
If yes, finish the definition of the optimization problem and save your
definition.<ul class = "ul">

<li class = "li"><p>In GUI:
Save as &lt;jobname&gt;.par.</p></li> 
</ul></li></ul>
<p>The essential commands required for the optimization model in shape optimization
are described in the following. The order of their appearance corresponds
to the order of the above listed procedures.</p>
<p>The definitions for the optimization job are assembled in a parameter
file. The exact syntax of the commands can be looked up in commands manual.
The following figure gives an overview of a standard optimization task
and the relation between the several commands. Only commands which are
referenced in the <span class = "ph uicontrol">OPTIMIZE</span> command will be included in the
optimization.</p>
<table class = "table" id = "tso-c-usr-shape-optTaskOvw__ae230908"><caption/><colgroup><col/></colgroup><tbody class = "tbody">
<tr class = "row">
<td class = "entry"><br/><img class = "image" src = "../TsoUserImages/shape_blockstructure.png" width = "492" height = "191"/><br/></td>
</tr>
</tbody></table>

</div>

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