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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>Optimizer Parameters</h1></td></tr><tr><td class = "DocHeader4" colspan = "2"/></tr><tr><td class = "DocHeader3"><table class = "DocHeaderIntro" id = "table12"><tr><td class = "Intro1Only"><p class = "header"><p class = "abstract">
<span class = "shortdesc">The shell thicknesses of the structure are updated using the
method of Convex Separable Approximations (CSA), see Svanberg (2002). Normally, the
update method suggested in Svanberg (2002) is stable. However, if the
design responses are very sensitive, it is suggested to use a more conservative
update method that requires more optimization iterations. </span>

</p>

</p></td></tr></table></td><td class = "DocHeader2"><table class = "DocTopicsSeeAlso" id = "table13"><tr><td class = "TopicsTitle">See Also</td></tr></table><table class = "DocTopicsInOtherGuides" id = "table14"><tr><td height = "8px"/></tr><tr><td class = "TopicsTitleNormal">In Other Guides</td></tr><tr><td><a title = "Defines parameters to control optimization." href = "../TsoCmdMap/tso-r-cmd-optParam.htm#tso-r-cmd-optParam">OPT_PARAM</a></td></tr></table></td></tr></table>




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<p>The update strategy is changed using the parameter <code class = "ph codeph">THICKNESS_UPDATE</code>.
The default value of <code class = "ph codeph">THICKNESS_UPDATE</code> is NORMAL. Setting
<code class = "ph codeph">THICKNESS_UPDATE</code> to <code class = "ph codeph">CONSERVATIVE</code>
leads to a conservative update of the design variables:</p>
<pre class = "codeblock">
<code class = "ph codeph">
OPT_PARAM
 ID_NAME          = opt_params
 OPTIMIZE         = id_of_optimize
 THICKNESS_UPDATE = CONSERVATIVE
END_
</code>
</pre>
<table class = "Remark" id = "table132"><tr><td class = "Remark"><span class = "run-in.important">Important:
				</span><span class = "notecontent"><p>It is recommended to use the conservative update method if it is problematic
to fulfill the constraints used in the optimization formulation.</p>
</span></td></tr></table>
<p>In addition, you can use a more aggressive update method of the design variables to reduce the
   number of optimization iterations by setting <code class = "ph codeph">THICKNESS_UPDATE</code> to
    <code class = "ph codeph">AGGRESSIVE</code>:</p>
<pre class = "codeblock">
<code class = "ph codeph">
OPT_PARAM
 ID_NAME          = opt_params
 OPTIMIZE         = id_of_optimize
 THICKNESS_UPDATE = AGGRESSIVE
END_
</code>
</pre>
<table class = "Remark" id = "table132"><tr><td class = "Remark"><span class = "run-in.warning">Warning:
				</span><span class = "notecontent"><p>This might lead to unstable optimization or prevent the convergence.</p></span></td></tr></table>

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