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      <div class="title_refTopic" id="xps10_pagetitle">CBUSH </div>
      <hr noshade="true">
      <h4 class="refClassification">Generalized Spring-and-Damper Connection </h4>
      <p class="para_refTopic">Defines a generalized spring-and-damper structural element that may be nonlinear or frequency dependent. </p>
      <div class="title_refCategory">Format: </div>
      <div class="refCategoryContent">
         <table border="1" width="100%" align="center">
            <colgroup span="1">
               <col span="1" width="10*">
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               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
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               <col span="1" width="10*">
            </colgroup>
            <thead>
               <tr>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">1 </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">4 </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">6 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">7 </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">9 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">10 </p>
                  </td>
               </tr>
            </thead>
            <tbody>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">CBUSH </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">GA </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">GB </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">GO/X1 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">X2 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">X3 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">CID </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">S </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">OCID </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">S1 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">S2 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">S3 </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 1: </div>
      <div class="refCategoryContent"></div>
      <div class="title_refCategory">Noncoincident grid points. </div>
      <div class="refCategoryContent">
         <table border="1" width="100%" align="center">
            <colgroup span="1">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
            </colgroup>
            <tbody>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">CBUSH </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">39 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">6 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">1 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">100 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">75 </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 2: </div>
      <div class="refCategoryContent"></div>
      <div class="title_refCategory">GB not specified. </div>
      <div class="refCategoryContent">
         <table border="1" width="100%" align="center">
            <colgroup span="1">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
            </colgroup>
            <tbody>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">CBUSH </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">39 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">6 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">1 </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">0 </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 3: </div>
      <div class="refCategoryContent"></div>
      <div class="title_refCategory">Coincident grid points (GA=GB). </div>
      <div class="refCategoryContent">
         <table border="1" width="100%" align="center">
            <colgroup span="1">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
            </colgroup>
            <tbody>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">CBUSH </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">39 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">6 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">1 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">100 </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">6 </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 4: </div>
      <div class="refCategoryContent"></div>
      <div class="title_refCategory">Noncoincident grid points with fields 6 through 9 blank and a spring-damper offset. </div>
      <div class="refCategoryContent">
         <table border="1" width="100%" align="center">
            <colgroup span="1">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
               <col span="1" width="10*">
            </colgroup>
            <tbody>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">CBUSH </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">39 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">6 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">1 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">600 </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>
               <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">0.25 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">10 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">0. </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">10. </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">10. </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="10" width="100%" align="center">
            <colgroup span="1">
               <col span="1" width="16*">
               <col span="1" width="84*">
            </colgroup>
            <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) </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 PBUSH entry.  (Integer &gt; 0; Default = EID) </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">GA, GB </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Grid point identification number of connection points.  See Remark <a class="links" href="javascript:void(0)" onclick="top.openFile('QRG/13topic_13.html#refNqin337juli');return(false);">18-6</a> (Integer &gt; 0) 
                     </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Xi </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Components of orientation vector</p>
                     <p class="para_td"> <img align="bottom" src="graphics/bulkc1-ufig03.gif" border="0">, from GA, in the displacement coordinate system at GA.  (Real) 
                     </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">GO </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Alternate method to supply vector </p>
                     <p class="para_td"><img align="bottom" src="graphics/bulkc1-ufig03.gif" border="0"> using grid point GO.  Direction of <img align="bottom" src="graphics/bulkc1-ufig03.gif" border="0"> is from GA to GO. <img align="bottom" src="graphics/bulkc1-ufig03.gif" border="0"> is then transferred to end A.  See Remark <a class="links" href="javascript:void(0)" onclick="top.openFile('QRG/13topic_13.html#ref2qin1bbjuli');return(false);">18-3</a>. (Integer &gt; 0) 
                     </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">CID </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Element coordinate system identification.  A 0 means the basic coordinate system.  If CID is blank, then the element coordinate system is determined from GO or Xi.  See <a class="links" href="javascript:void(0)" onclick="top.openFile('QRG/13topic_13.html#ref40008');return(false);">Figure 12-</a> and Remark <a class="links" href="javascript:void(0)" onclick="top.openFile('QRG/13topic_13.html#ref2qin1bbjuli');return(false);">18-3</a>. (Integer &ge; 0 or blank) 
                     </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">S </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Location of spring damper.  See <a class="links" href="javascript:void(0)" onclick="top.openFile('QRG/13topic_13.html#ref40008');return(false);">Figure 12-</a>.  (0.0 &le; Real &le; 1.0; Default = 0.5) 
                     </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">OCID </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Coordinate system identification of spring-damper offset.  See Remark <a class="links" href="javascript:void(0)" onclick="top.openFile('QRG/13topic_13.html#refkvzKo201lori');return(false);">18-9</a>. (Integer &ge; -1; Default = -1, which means the offset point lies on the line between GA and GB according to <a class="links" href="javascript:void(0)" onclick="top.openFile('QRG/13topic_13.html#ref40008');return(false);">Figure 12-</a>.) 
                     </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">S1, S2, S3 </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Components of spring-damper offset in the OCID coordinate system if OCID &ge; 0.  See <a class="links" href="javascript:void(0)" onclick="top.openFile('QRG/13topic_13.html#ref28089');return(false);">Figure 12-</a> and Remark <a class="links" href="javascript:void(0)" onclick="top.openFile('QRG/13topic_13.html#refkvzKo201lori');return(false);">18-9</a>.. (Real) 
                     </p>
                  </td>
               </tr>
            </tbody>
         </table><br></div>
      <div class="title_refCategory">Remarks: </div>
      <div class="refCategoryContent">
         <ol type="1" start="1">
            <li>
               <p class="para_item">Element identification numbers should be unique with respect to all other element identification numbers. </p>
            </li>
            <li><a name="ref29518"></a><p class="para_item"><a class="links" href="javascript:void(0)" onclick="top.openFile('QRG/13topic_13.html#ref40008');return(false);">Figure 12-</a> shows the bush element geometry. 
               </p>
            </li>
            <li><a name="ref2qin1bbjuli"></a><p class="para_item">CID &ge; 0 overrides GO and Xi.  Then the element x-axis is along T1, the element y-axis is along T2, and the element z-axis is along T3 of the CID coordinate system.  If the CID refers to a cylindrical coordinate system or a spherical coordinate system, then grid GA is used to locate the system.  For cylindrical or spherical coordinate systems, if GA falls on the z-axis used to define them, it is recommended that another CID be selected to define the element x-axis. </p>
            </li>
            <li>
               <p class="para_item">For noncoincident grids (GA &ne; GB), when GO or X1, X2, X3 is given and no CID is specified, the line AB is the element x-axis and the orientation vector <img align="bottom" src="graphics/bulkc1-ufig03.gif" border="0"> lies in the x-y plane (similar to the CBEAM element). 
               </p>
            </li>
            <li>
               <p class="para_item">For noncoincident grids (GA &ne; GB), if neither GO or X1, X2, X3 is specified and no CID is specified, then the line AB is the element x-axis.  This option is valid only when K1 (or B1) or K4 (or B4) or both are specified on the PBUSH entry (but K2, K3, K5, K6 or B2, B3, B5, B6 are not specified).  If K2, K3, K5, or K6 (or B2, B3, B5, or B6) are specified, a fatal message will be issued. </p>
            </li>
            <li><a name="refNqin337juli"></a><p class="para_item">If GA and GB are coincident, or if GB is blank, then CID must be specified. </p>
            </li>
            <li>
               <p class="para_item">If PID references a PBUSHT entry, then the CBUSH element may only be defined in the residual structure and cannot be attached to any omitted degrees-of-freedom. </p>
            </li>
            <li>
               <p class="para_item">Element impedance output is computed in the CID coordinate system.  The impedances in this system are uncoupled. </p>
            </li>
            <li><a name="refkvzKo201lori"></a><p class="para_item">If OCID = -1 or blank (default) then S is used and S1, S2, S3 are ignored.  If OCID &ge; 0, then S is ignored and S1, S2, S3 are used. </p><a name="ref40008"></a><div class="figure">
                  <p align="center"><img align="bottom" src="graphics/bulkc1-fig16.gif"></p>
               </div>
               <div class="title_figure">Figure. CBUSH Element </div><a name="ref28089"></a><div class="figure">
                  <p align="center"><img align="bottom" src="graphics/bulkc1-fig17.gif"></p>
               </div>
               <div class="title_figure">Figure. Definition of Offset S1, S2, S3 </div>
            </li>
            <li>
               <p class="para_item">When CID &ge; 0, the element x-axis is set as in Remark <a class="links" href="javascript:void(0)" onclick="top.openFile('QRG/13topic_13.html#ref29518');return(false);">18-2</a>. This means that the element force is always computed as Ke. (UB − UA); if UA &gt; UB, a compressive force will result. This is unlike the GO or Xi options, where relative positive elongation is tension and relative negative elongation is compression. 
               </p>
            </li>
         </ol>
      </div>
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