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      <div class="title_refTopic" id="xps10_pagetitle">CTETRA </div>
      <hr noshade="true">
      <h4 class="refClassification">Four-Sided Solid Element Connection </h4>
      <p class="para_refTopic">Defines the connections of the four-sided solid element with four to ten grid points. </p>
      <div class="title_refCategory">Format: </div>
      <div class="refCategoryContent">
         <table border="1" width="100%" align="center">
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            <thead>
               <tr>
                  <th align="center" colspan="1" rowspan="1">
                     <p class="para_th">1 </p>
                  </th>
                  <th align="center" colspan="1" rowspan="1">
                     <p class="para_th">2 </p>
                  </th>
                  <th align="center" colspan="1" rowspan="1">
                     <p class="para_th">3 </p>
                  </th>
                  <th align="center" colspan="1" rowspan="1">
                     <p class="para_th">4 </p>
                  </th>
                  <th align="center" colspan="1" rowspan="1">
                     <p class="para_th">5 </p>
                  </th>
                  <th align="center" colspan="1" rowspan="1">
                     <p class="para_th">6 </p>
                  </th>
                  <th align="center" colspan="1" rowspan="1">
                     <p class="para_th">7 </p>
                  </th>
                  <th align="center" colspan="1" rowspan="1">
                     <p class="para_th">8 </p>
                  </th>
                  <th align="center" colspan="1" rowspan="1">
                     <p class="para_th">9 </p>
                  </th>
                  <th align="center" colspan="1" rowspan="1">
                     <p class="para_th">10 </p>
                  </th>
               </tr>
            </thead>
            <tbody>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">CTETRA </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">EID </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">PID </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">G1 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">G2 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">G3 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">G4 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">G5 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">G6 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">&nbsp; </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">&nbsp; </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">G7 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">G8 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">G9 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">G10 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">&nbsp; </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">&nbsp; </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">&nbsp; </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">&nbsp; </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">&nbsp; </p>
                  </td>
               </tr>
            </tbody>
         </table><br></div>
      <div class="title_refCategory">Example: </div>
      <div class="refCategoryContent">
         <table border="1" width="100%" align="center">
            <colgroup span="1">
               <col span="1" width="10*">
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            <tbody>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">CTETRA </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">112 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">2 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">3 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">15 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">14 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">4 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">103 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">115 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">&nbsp; </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">&nbsp; </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">5 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">16 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">8 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">27 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">&nbsp; </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">&nbsp; </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">&nbsp; </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">&nbsp; </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">&nbsp; </p>
                  </td>
               </tr>
            </tbody>
         </table><br></div>
      <div class="title_refCategory">Fields:</div>
      <div class="refCategoryContent">
         <table cellpadding="9" width="100%" align="center">
            <colgroup span="1">
               <col span="1" width="16.01*">
               <col span="1" width="83.99*">
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            <thead>
               <tr>
                  <th align="left" colspan="1" rowspan="1">
                     <p class="para_th"><b class="uiTerm">Field </b></p>
                  </th>
                  <th align="left" colspan="1" rowspan="1">
                     <p class="para_th"><b class="uiTerm">Contents </b></p>
                  </th>
               </tr>
            </thead>
            <tbody>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">EID </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Element identification number. (Integer &gt; 0; Required) </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">PID </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Property identification number of a PSOLID or PLSOLID entry. (Integer &gt; 0) </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Gi </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Identification numbers of connected grid points. (Integer &gt; 0 or blank) </p>
                  </td>
               </tr>
            </tbody>
         </table><br><a name="ref55288"></a><div class="figure">
            <p align="center"><img align="bottom" src="graphics/bulkc2-fig28.gif"></p>
         </div>
         <div class="title_figure">Figure. CTETRA Element Connection </div>
      </div>
      <div class="title_refCategory">Remarks: </div>
      <div class="refCategoryContent">
         <ol type="1" start="1">
            <li>
               <p class="para_item">Element ID numbers must be unique with respect to all other element ID numbers. </p>
            </li>
            <li>
               <p class="para_item">The topology of the diagram must be preserved, i.e., G1, G2, G3 define a triangular face; G1, G8, and G4 are on the same edge, etc. </p>
            </li>
            <li>
               <p class="para_item">The edge points, G5 to G10, are optional.  Any or all of them may be deleted.  If the ID of any edge connection point is left blank or set to zero, the equations of the element are adjusted to give correct results for the reduced number of connections.  Corner grid points cannot be deleted.  The element is an isoparametric element in all cases. </p>
            </li>
            <li>
               <p class="para_item">Components of stress are output in the material coordinate system except for hyperelastic elements, which are output in the basic coordinate system. </p>
            </li>
            <li>
               <p class="para_item">For nonhyperelastic elements, the element coordinate system is derived from the three vectors R, S, and T, which join the midpoints of opposite edges. </p>
               <p class="para_item">R vector joins midpoints of edges G1-G2 and G3-G4. </p>
               <p class="para_item">S vector joins midpoints of edges G1-G3 and G2-G4. </p>
               <p class="para_item">T vector joins midpoints of edges G1-G4 and G2-G3. </p>
               <p class="para_item">The origin of the coordinate system is located at G1.  The element coordinate system is chosen as close as possible to the R, S, and T vectors and points in the same general direction.  (Mathematically speaking, the coordinate system is computed in such a way that, if the R, S, and T vectors are described in the element coordinate system, a 3x3 positive definite symmetric matrix would be produced.) </p><a name="ref65495"></a><div class="figure">
                  <p align="center"><img align="bottom" src="graphics/bulkc2-fig29.gif"></p>
               </div>
               <div class="title_figure">Figure. CTETRA Element R, S, and T Vectors </div>
            </li>
            <li>
               <p class="para_item">It is recommended that the edge points be located within the middle third of the edge. </p>
            </li>
            <li>
               <p class="para_item">For hyperelastic elements, the plot codes are specified under the CTETRAFD element name in <a class="links" href="javascript:void(0)" onclick="top.openFile('QRG/09ref75809_1.html');return(false);">&ldquo;Item Codes&rdquo;</a>. 
               </p>
            </li>
            <li>
               <p class="para_item">If a CTETRA element is referenced by a PSET or PVAL entry, then p-version formulation is used and the element can have curved edges. </p>
               <ul>
                  <li>
                     <p class="para_item">If a curved edge of a p-element is shared by an h-element without midside nodes, the geometry of the edge is ignored and set straight. </p>
                  </li>
                  <li>
                     <p class="para_item">Elements with midside nodes cannot be p-elements and edges with midside nodes cannot be shared by p-elements. </p>
                  </li>
               </ul>
            </li>
            <li>
               <p class="para_item">By default, all of the six edges of the element are considered straight unless: </p>
               <ul>
                  <li>
                     <p class="para_item">For p-elements, there is an FEEDGE or FEFACE entry that contains the two grids of any edge of this element.  In this case, the geometry of the edge is used in the element. </p>
                  </li>
                  <li>
                     <p class="para_item">For h-elements, any of G5 through G10 are specified. </p>
                  </li>
               </ul>
            </li>
         </ol>
      </div>
      <div class="title_refCategory">Remarks related to SOLs 601 and 701: </div>
      <div class="refCategoryContent">
         <ol type="1" start="1">
            <li>
               <p class="para_item">For SOL 601, only elements with 4 or 10 grid points are allowed, i.e., either all edge points G5 to G10 are specified or no edge points are specified. For SOL 701, only elements with 4 grid points are allowed. </p>
            </li>
            <li>
               <p class="para_item">For SOL 601, when ELCV=1 is specified in NXSTRAT (see Remark 2 (SOL 601) in the CHEXA entry), 10-node CTETRA elements will be converted to 11-node elements (with 1 additional node at the centroid of the element). </p>
            </li>
         </ol>
      </div>
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