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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>Maximizing the Eigenfrequency of a Certain Eigenmode</h1></td></tr><tr><td class = "DocHeader4" colspan = "2"/></tr><tr><td class = "DocHeader3"><table class = "DocHeaderIntro" id = "table12"><tr><td class = "Intro1"><p class = "header"><p class = "abstract">
<span class = "shortdesc">
You can increase a specific eigenfrequency in
the eigenfrequency spectrum belonging to a certain eigenmode. In this case, a specific eigenfrequency is defined using <code class = "ph codeph">TYPE = DYN_FREQ</code>.
</span>

</p>
<p>This task shows you how to:
					</p><ul><li><a href = "#tso-t-user-TopOpt-ModAna-MaxFr-guiDesResp" id = "toc_rg" title = "">
Define a Design Response for a Specific Eigenfrequency in <span class = "ph">Tosca Structure.gui</span>
</a></li></ul>
</p></td></tr><tr><td class = "Intro2"><hr class = "header"/><span class = "run-in-beforeyoubegin">Before you begin: </span>
<p>When optimizing a specific eigenfrequency, the order of the eigenfrequencies
might change during the optimization iterations. Consequently, the eigenfrequencies might must be tracked during
the optimization iterations. This is done by mode tracking. For more information, 
see <a class = "xref" href = "tso-c-user-TopOpt-Sett-Sensi-ModTrack.htm#tso-c-user-TopOpt-Sett-Sensi-ModTrack" title = "It is possible to apply a simple mode tracking function for the modal analysis using the modal assurance criterion (MAC) including a mass weighting. An example is given in the Tosca Structure Examples Guide">Mode Tracking</a>.</p>
</td></tr></table></td><td class = "DocHeader2"><table class = "DocTopicsSeeAlso" id = "table13"><tr><td class = "TopicsTitle">See Also</td></tr><tr><td><a title = "This section describes the theory of eigenfrequency." href = "tso-c-usr-terms-eigfreqOvw.htm#tso-c-usr-terms-eigfreqOvw">Overview of Eigenfrequency</a></td></tr></table></td></tr></table>



<div class = "body taskbody">
<div class = "p"><!--xxx--></div>

<section><div class = "li step p">
By default, the modes are not tracked during the optimization. Mode
tracking is activated in <code class = "ph codeph">OPT_PARAM</code> command:
<p>
<pre class = "codeblock">
<code class = "ph codeph">
DRESP
 ID_NAME      = single_lowest_eigenfrequency_1
 DEF_TYPE     = SYSTEM
 TYPE         = DYN_FREQ
 LC_SET       = MODAL, ALL, 1
END_
  
OBJ_FUNC
 ID_NAME      = maximize_single_eigenfrequency
 DRESP        = single_lowest__1
 TARGET       = MAX
END_
  
OPT_PARAM
 ID_NAME      = opt_params
 OPTIMIZE     = maximize_single_eigenfrequency
 MODETRACKING = ON
 MODENUMBERS  = 8
END_
</code>
</pre>
<p>For this example, at least 8 eigenfrequencies should be requested in the
finite element input model defined by the user.</p>
</p>
</div></section>
</div>


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<article class = "topic task nested1" aria-labelledby = "ariaid-title2" id = "tso-t-user-TopOpt-ModAna-MaxFr-guiDesResp">
<h2 class = "title topictitle2">
Define a Design Response for a Specific Eigenfrequency in <span class = "ph">Tosca Structure.gui</span>
</h2>

<div class = "body taskbody">
<section><ol class = "ol steps"><li class = "li step stepexpand">
To create a new Design Response, select <span class = "ph uicontrol">Command &gt;</span> <span class = "ph uicontrol">DRESP</span>.
<div class = "itemgroup stepresult">The DRESP dialog appears.</div>
</li><li class = "li step stepexpand">
Set <span class = "ph uicontrol">DefType = System</span>,
<span class = "ph uicontrol">Category = Base</span> and <span class = "ph uicontrol">Type = DYN_FREQ</span>.

</li><li class = "li step stepexpand">
Choose the <span class = "ph">load case</span>
     by clicking <span class = "ph uicontrol">Add LC</span> and setting <span class = "ph uicontrol">Analysis Type</span>
     to <span class = "ph uicontrol">MODAL</span>, entering the 
	 <span class = "ph">load case</span> 
	 ID and the numbers of eigenmodes (for example, 1) in the <span class = "ph uicontrol">Eigenmode/Subcase</span>
     field. 
	 <br/><img class = "image" src = "../TsoUserImages/topo_dresp_eigenfreq_dialog_3.png" width = "450"/><br/>

</li></ol></section>
</div>

</article>


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