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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>
Settings for <span class = "ph">Tosca Structure.shape</span>
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<span class = "shortdesc">
<span class = "ph">Tosca Structure.shape</span>
contains various settings that might be applied to both, the controller-based and the sensitivity-based shape optimization approach. These settings are introduced in this chapter.
</span>

</p>
<p>This page discusses: </p><ul><li><a href = "#tso-c-usr-shape-settingsGen__tso-c-usr-shape-settingGens-midNodes" id = "toc_rg" title = "">Treatment of the Midside Nodes (MID_NODES) </a></li><li><a href = "#tso-c-usr-shape-settingsGen__tso-c-usr-shape-settingsGen-vector" id = "toc_rg" title = "">Updating the Optimization Displacement Vectors (VECTOR) </a></li></ul>
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<div class = "body conbody">

<div class = "section" id = "tso-c-usr-shape-settingsGen__tso-c-usr-shape-settingGens-midNodes"><h2 class = "title sectiontitle">Treatment of the Midside Nodes (MID_NODES) </h2>

<p> Only corner nodes (from finite elements) are supported as design nodes. Midside nodes may
be included in the design node group, but the optimization displacement of the midside nodes
of second-order elements is interpolated from the optimization displacement of the adjacent
corner nodes. </p><p>The
interpolation method can be chosen with the <code class = "ph codeph">MID_NODES</code>
parameter:
</p>
<pre class = "codeblock">
...
MID_NODES = [ LINEAR | INTERPOLATE ]
...
</pre>
<p><ul class = "ul">
<li class = "li">With the default option, <code class = "ph codeph">LINEAR</code> the midside node positions
are linearly interpolated from the optimized position of the connected
corner nodes. </li>
<li class = "li">With the option <code class = "ph codeph">INTERPOLATE</code>, the midside
node-based optimization displacements are interpolated from the optimization
displacement of the connected corner nodes.
</li></ul></p>
<div class = "note"><span class = "run-in.note">Note:
			</span><span class = "notecontent"><p>In the initial position, if the midside node is on the line between the corner nodes, there will be
no difference between the two methods. But if the edge of the element
is bent only with <code class = "ph codeph">INTERPOLATE</code>, the bending can be prevented.
</p></span></div>

</div>


<div class = "section" id = "tso-c-usr-shape-settingsGen__tso-c-usr-shape-settingsGen-vector"><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">Updating the Optimization Displacement Vectors (VECTOR) </h2>

<p>An optimization displacement vector is determined by the optimization
algorithm for every design node. This vector graphically corresponds
to the outer surface unit normal at the node and indicates the optimization
displacement direction. Restrictions influencing the direction (<code class = "ph codeph">DVCON_SHAPE</code>
with <code class = "ph codeph">CHECK_DOF</code> and <code class = "ph codeph">CHECK_BC</code>) are included
in the calculation of the optimization displacement vectors.</p>
<p>The <code class = "ph codeph">VECTOR</code>
parameter enables the user to specify the design cycle in which to
determine the optimization displacement vectors:
</p>
<pre class = "codeblock">
...
VECTOR = [ EVER | FIRST ]
...
</pre>
<p>
<ul class = "ul"><li class = "li">The default setting is <code class = "ph codeph">VECTOR=EVER</code>. The optimization
displacement vectors are redetermined in every design cycle by the optimization
algorithm and consequently adjusted to changed conditions (for example
shape of the structure, effective restrictions, mesh quality, etc.).</li>
<li class = "li">With the setting <code class = "ph codeph">VECTOR=FIRST</code>, the optimization displacement
vectors are calculated only once in the first design cycle and then kept
constant in all other cycles. The optimization displacement vectors
are not adjusted to changes in conditions during the remaining part of
the optimization. </li></ul>
</p>
<p>The following figure provides an illustration of
the two settings. Generally, <code class = "ph codeph">VECTOR=EVER</code> provides better
results since the mesh smoothing algorithm is less restricted and a better
mesh can be achieved. However, in certain cases the setting <code class = "ph codeph">VECTOR=FIRST</code>
can be of advantage.
</p>
<table class = "table" id = "tso-c-usr-shape-settingsGen__ae234372"><caption/><colgroup><col/></colgroup><tbody class = "tbody">
<tr class = "row">
<td class = "entry"><br/><img class = "image" src = "../TsoUserImages/shape_disp_vector.png" width = "450"/><br/></td>
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