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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>General</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">This section shows you how to work with design variable restrictions
in bead optimization setups.</span>

</p>
<ul><li><a href = "#tso-c-usr-bead-restrictions-general__tso-c-usr-restrictionsBeadGeneral-restrictions" id = "toc_rg" title = "">Restrictions for Bead Optimization</a></li></ul>
</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 restrictions of the design variables in bead optimization." href = "../TsoCmdMap/tso-r-cmd-dvconBead.htm#tso-r-cmd-dvconBead">DVCON_BEAD</a></td></tr></table></td></tr></table>




<div class = "body conbody">
<p>Restrictions in bead optimization can either be defined as boundary
conditions that limit the node displacement or as a LINK-condition.
The latter is only allowed for controller-based bead optimization. A
design variable constraint is a restriction that directly affects the
individual design variables or the individual design nodes.</p>
<p>Possible restrictions are: <ul class = "ul">
<li class = "li">the specification of an allowable displacement area by limiting the signed absolute displacement.</li>
<li class = "li">the specification of variation and frozen areas.</li></ul> </p>
<p>It is also possible to influence the allowable displacement direction by limiting the
   displacement to specific coordinate directions. In addition, it is possible to link the design
   variables and to force them to be optimized in a symmetric way (only controller).</p>
<p>The definition of the design variable constraints for bead optimization
   is done using the <a class = "xref" href = "../TsoCmdMap/tso-r-cmd-dvconBead.htm#tso-r-cmd-dvconBead" title = "Defines restrictions of the design variables in bead optimization.">DVCON_BEAD</a>
   command.</p>
<p><table class = "Remark" id = "table132"><tr><td class = "Remark"><span class = "run-in.important">Important:
				</span><span class = "notecontent"><p><ol class = "ol" id = "tso-c-usr-bead-restrictions-general__ol_CCF2B4244A8B42488E28561FC651431F">
<li class = "li">Possible restrictions for bead optimization are very similar to the
                                             restrictions of shape optimization. The definition
                                             of the <code class = "ph codeph">CHECK</code> parameters is often identical.</li>
<li class = "li">Some of the design variable constraints for bead optimization relate
                                             not only to the design variable itself but also to the corresponding
                                             optimization displacement vectors or the design coordinates. The term
                                             ‘design variable constraint’ in this case should be interpreted in
                                             a more general way.</li>
</ol></p></span></td></tr></table>
</p>

<div class = "section" id = "tso-c-usr-bead-restrictions-general__tso-c-usr-restrictionsBeadGeneral-restrictions"><h2 class = "title sectiontitle">Restrictions for Bead Optimization</h2>

<p>The following individual restrictions can be defined for bead optimization:</p>
<ul class = "ul" id = "tso-c-usr-bead-restrictions-general__ul_8ED4C566A3584168BB8CE733263DF726">
<li class = "li">CHECK_BC, CHECK_DOF: Restriction of the displacement direction
                                             (see <a class = "xref" href = "tso-c-usr-bead-restrictions-DispDirection.htm#tso-c-usr-bead-restrictions-DispDirection" title = "This section shows you how to influence and restrict the displacement direction of design nodes.">Restricting the Direction of Displacement</a>)</li>
<li class = "li">CHECK_ELGR: Check the displacements against elements of an element group
                                             (see <a class = "xref" href = "tso-c-usr-bead-restrictions-CheckElgr.htm#tso-c-usr-bead-restrictions-CheckElgr" title = "Limit node growth with CHECK_ELGR.">Displacement Check against Elements (CHECK_ELGR)</a>)</li>
<li class = "li">CHECK_TYPE = FILTER: Sets a new filter type on the restriction node group.
     (see <a class = "xref" href = "tso-c-usr-bead-restrictions-Filter.htm#tso-c-usr-bead-restrictions-Filter" title = "You can define a filter restriction with additional settings for the restriction group. With it, a more consistent workflow between bead and other optimization types is achieved. In addition, it tends to lead to a better optimization convergence behavior.">Filter Restriction (CHECK_TYPE=FILTER)</a>)</li>
<li class = "li">CHECK_GROW: Restriction of the absolute displacement in shell normal direction 
                                             (see <a class = "xref" href = "tso-c-usr-bead-restrictions-AbsoluteDisplacement.htm#tso-c-usr-bead-restrictions-AbsoluteDisplacement" title = "This section gives information on the CHECK_SHRINK and CHECK_GROW design variable constraints.">Restricting the Absolute Displacement</a>)</li>
<li class = "li">CHECK_LINK: Assignment of a coupling condition  (only BEAD_CONTROLLER)
                                             (see <a class = "xref" href = "tso-c-usr-bead-restrictions-CheckLink.htm#tso-c-usr-bead-restrictions-CheckLink" title = "This section gives information on how to link nodes with other nodes.">Symmetry Conditions (CHECK_LINK)</a>)</li>
<li class = "li">CHECK_SHRINK: Restriction of the absolute displacement opposite the shell normal direction
                                             (see <a class = "xref" href = "tso-c-usr-bead-restrictions-AbsoluteDisplacement.htm#tso-c-usr-bead-restrictions-AbsoluteDisplacement" title = "This section gives information on the CHECK_SHRINK and CHECK_GROW design variable constraints.">Restricting the Absolute Displacement</a>)</li>
<li class = "li">CHECK_SOLID: Check the displacements against geometric primitive solids
                                             (see <a class = "xref" href = "tso-c-usr-bead-restrictions-CheckSolid.htm#tso-c-usr-bead-restrictions-CheckSolid" title = "This section gives information on the CHECK_SOLID design variable constraint.">Displacement Check against Solids (CHECK_SOLID)</a>)</li>
</ul>
<p><table class = "Remark" id = "table132"><tr><td class = "Remark"><span class = "run-in.important">Important:
				</span><span class = "notecontent"><p><ol class = "ol" id = "tso-c-usr-bead-restrictions-general__ol_1CAD3B29134F41E1B137F26593EAF3CA">
<li class = "li">Using <code class = "ph codeph">CHECK_GROW</code> and <code class = "ph codeph">CHECK_SHRINK</code>  is the easiest way
                                             to constrain design nodes for sensitivity-based optimization. See also
<a class = "xref" href = "tso-c-usr-bead-restrictions-AbsoluteDisplacement.htm#tso-c-usr-bead-restrictions-AbsoluteDisplacement" title = "This section gives information on the CHECK_SHRINK and CHECK_GROW design variable constraints.">Restricting the Absolute Displacement</a>.</li>
<li class = "li"><code class = "ph codeph">CHECK_SHRINK</code> has no effect on the
                                             controller algorithm while it only "grows."</li>
<li class = "li"><code class = "ph codeph">CHECK_LINK</code> has no effect on the sensitivity-based algorithm. </li>
<li class = "li">The restrictions are checked only for the corner nodes
                                             of the node group (<code class = "ph codeph">ND_GROUP</code> parameter). If midside nodes are
                                             contained in the node group, they are subsequently placed in between the neighboring
                                             corner nodes. Therefore, it is impossible for midside nodes to guarantee adherence
                                             to the restrictions; a small amount of deviation might occur.</li>
<li class = "li">It is possible to define several individual
                                             <code class = "ph codeph">CHECK_*</code> restrictions within a <code class = "ph codeph">DVCON_BEAD</code>
                                             command. The order of the execution of the individual restrictions within a
                                             <code class = "ph codeph">DVCON_BEAD</code> command appears as follows: <code class = "ph codeph">CHECK_GROW,
                                             CHECK_SOLID, CHECK_ELGR, CHECK_BC, CHECK_DOF, CHECK_LINK</code>. <p>The
                                             individual restrictions are checked independently of each other (an
                                             individual restriction always overrides the previous restriction).</p></li>
<li class = "li">The activated <code class = "ph codeph">DVCON_BEAD</code> entries are
                                             executed in the order in which they are referenced in the <code class = "ph codeph">OPTIMIZE</code>
                                             command. The individual <code class = "ph codeph">DVCON_BEAD</code> entries are checked
                                             independently of each other (that is, a <code class = "ph codeph">DVCON_BEAD</code> entry always
                                             overrides the previous <code class = "ph codeph">DVCON_BEAD</code> entry). If mutually independent
                                             restrictions are declared, all restrictions are observed. If mutually dependent
                                             restrictions are declared, the user must select an order of execution that is
                                             logical and specific to the problem.</li>
<li class = "li">It is possible to define several design variable constraints using
                                             the <code class = "ph codeph">DVCON_BEAD</code> command. Each <code class = "ph codeph">DVCON_BEAD</code> definition
                                             must have its own unique name.</li>
<li class = "li">The <code class = "ph codeph">DVCON_BEAD</code> definitions must be
                                             activated by a reference in the <code class = "ph codeph">OPTIMIZE</code> command. Nonactivated
                                             definitions have no influence on the optimization. The reference in the
                                               <code class = "ph codeph">OPTIMIZE</code> command assigns the design variable constraints and the
                                             design area (see <code class = "ph codeph">DV_BEAD</code> command) to each other. The recommended
                                             procedure is to define the assigned restrictions immediately after defining the
                                             design area.</li>
</ol></p></span></td></tr></table>

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