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      <title>PBUSH1D</title>
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      <div class="title_refTopic" id="xps10_pagetitle">PBUSH1D </div>
      <hr noshade="true">
      <h4 class="refClassification">Rod Type Spring-and-Damper Property </h4>
      <p class="para_refTopic">Defines linear and nonlinear properties of a one-dimensional spring and damper element (CBUSH1D entry). </p>
      <div class="title_refCategory">Format: </div>
      <div class="refCategoryContent">
         <table border="1" width="100%" align="center">
            <colgroup span="1">
               <col span="1" width="1206*">
               <col span="1" width="1061*">
               <col span="1" width="982*">
               <col span="1" width="982*">
               <col span="1" width="982*">
               <col span="1" width="971*">
               <col span="1" width="971*">
               <col span="1" width="982*">
               <col span="1" width="971*">
               <col span="1" width="881*">
            </colgroup>
            <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">PBUSH1D </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">K </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">C </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">M </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">SA </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">SE </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">&ldquo;SHOCKA&rdquo; </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">TYPE </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">CVT </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">CVC </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">EXPVT </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">EXPVC </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">IDTS </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">&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">IDETS </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">IDECS </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">IDETSD </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">IDECSD </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">&ldquo;SPRING&rdquo; </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">TYPE </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">IDT </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">IDC </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">IDTDU </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">IDCDU </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">&ldquo;DAMPER&rdquo; </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">TYPE </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">IDT </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">IDC </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">IDTDV </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">IDCDV </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">&ldquo;GENER&rdquo; </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">IDT </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">IDC </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">IDTDU </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">IDCDU </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">IDTDV </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">IDCDV </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="1138*">
               <col span="1" width="1179*">
               <col span="1" width="985*">
               <col span="1" width="985*">
               <col span="1" width="985*">
               <col span="1" width="985*">
               <col span="1" width="985*">
               <col span="1" width="985*">
               <col span="1" width="985*">
               <col span="1" width="882*">
            </colgroup>
            <tbody>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">PBUSH1D </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">35 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">3000. </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">200. </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">300. </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">SHOCKA </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">TABLE </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">2.2 </p>
                  </td>
                  <td align="center" colspan="1" rowspan="1">
                     <p class="para_td">1.2 </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">200 </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><p class="para_refCategory">The continuation entries are optional. The four options, SHOCKA, SPRING, DAMPER, and GENER can appear in any order </p>
      </div>
      <div class="title_refCategory">Fields:</div>
      <div class="refCategoryContent">
         <table cellpadding="9" width="100%" align="center">
            <colgroup span="1">
               <col span="1" width="15.97*">
               <col span="1" width="61.88*">
               <col span="1" width="22.15*">
            </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>
                  <th align="left" colspan="1" rowspan="1">
                     <p class="para_th"><b class="uiTerm">Default </b></p>
                  </th>
               </tr>
            </thead>
            <tbody>
               <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.  (Integer &gt; 0). </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Required </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">K </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Stiffness.  (Real &ge; 0). </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">See Remark <a class="links" href="javascript:void(0)" onclick="top.openFile('QRG/18topic_24.html#ref87494');return(false);">34-1. </a></p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">C </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Viscous damping.  (Real &ge; 0). </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">See Remarks <a class="links" href="javascript:void(0)" onclick="top.openFile('QRG/18topic_24.html#ref87494');return(false);">34-1</a> and <a class="links" href="javascript:void(0)" onclick="top.openFile('QRG/18topic_24.html#ref39634');return(false);">34-2. </a></p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">M </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Total mass of the element.  (Real &ge; 0). </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Blank </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">SA </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Stress recovery coefficient [1/area].  (Real &ge; 0). </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Blank </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">SE </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Strain recovery coefficient [1/length].  (Real &ge; 0). </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Blank </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">SHOCKA </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Character string specifying that the next 10 fieldsare coefficients of the following force versus velocity/displacement relationship.  (Character).</p>
                     <p class="para_td"><img align="bottom" src="graphics/bulkp-equ21.gif" border="0"></p>
                     <p class="para_td">The force F, the displacement u, and the velocity v, are in the axial direction of the damper.  The axis of the damper is defined by the two connecting grid points GA and GB on the CBUSH1D Bulk Data entry.  The displacement u and the velocity v, are the relative displacement and the relative velocity with respect to the grid point GA.  The scale factor S(u) must be defined with a table or with an equation. </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">&nbsp; </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">TYPE </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Character string indicating the type of definition.  (Character).  For TYPE = EQUAT, the fields IDETS, IDECS, IDETSD, and IDECSD are identification numbers of DEQATN entries.  For TYPE = TABLE the field IDTS is an identification number of a TABLEDi entry.  If no character string is provided (blanks), TYPE = TABLE is set. </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">TABLE </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">CVT </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Viscous damping coefficient C<sub class="subscript">V</sub> for tension v &gt; 0, force per unit velocity.  (Real). 
                     </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Required for SHOCKA </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">CVC </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Viscous damping coefficient C<sub class="subscript">V</sub> for compressionv &gt; 0, force per unit velocity.  (Real). 
                     </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">CVT </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">EXPVT </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Exponent of velocity EXPV for tension v &gt; 0.(Real). </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">1. </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">EXPVC </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Exponent of velocity EXPV for compression v &lt; 0.  (Real). </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">EXPVT </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">IDTS </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Identification number of a TABLEDi entry for tension and compression if TYPE = TABLE.  The TABLEDi entry defines the scale factor S, versus displacement u. </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Required for SHOCKA and TYPE=TABLE </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">IDETS </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Identification number of a DEQATN entry for tension if TYPE = EQUAT.  The DEQATN entry defines the scale factor S, versus displacement u, for tension u &gt; 0. </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Required for SHOCKA and TYPE=EQUAT </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">IDECS </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Identification number of a DEQATN entry for compression if TYPE = EQUAT.  The DEQATN entry defines the scale factor S, versus displacement u, for compression u &lt; 0. </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">IDETS </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">IDETSD </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Identification number of a DEQATN entry for tension if TYPE = EQUAT.  The DEQATN entry defines the derivative of the scale factor S, with respect to the displacement u, for tension u&gt;0. </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Required for SHOCKA and TYPE=EQUAT </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">IDECSD </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Identification number of a DEQATN entry for compression if TYPE = EQUAT.  The DEQATN entry defines the derivative of the scale factor S, with respect to the displacement u, for compression u &lt; 0. </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">IDETSD </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">SPRING </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Character string specifying that the next 5 fields define a nonlinear elastic spring element in terms of a force versus displacement relationship.  (Character).</p>
                     <p class="para_td"><img align="bottom" src="graphics/bulkp-equ22.gif" border="0"> 
                     </p>
                     <p class="para_td">Tension is u &gt; 0 and compression is u &lt; 0. </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">&nbsp; </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">DAMPER </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Character string specifying that the next 5 fields define a nonlinear viscous element in terms of a force versus velocity relationship.  (Character).</p>
                     <p class="para_td"><img align="bottom" src="graphics/bulkp-equ23.gif" border="0"></p>
                     <p class="para_td">Tension is v &gt; 0 and compression is v &lt; 0. </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">&nbsp; </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">GENER </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Character string specifying that the next 7 fields define a general nonlinear elastic spring and viscous damper element in terms of a force versus displacement and velocity relationship.  (Character).  For this element, the relationship can only be defined with TYPE = EQUAT.</p>
                     <p class="para_td"><img align="bottom" src="graphics/bulkp-equ24.gif" border="0"></p>
                     <p class="para_td">Tension is u &gt; 0 and compression is u &lt; 0.For SPRING, DAMPER, and GENER, the remaining fields are </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">&nbsp; </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">TYPE </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Character string indicating the type of definition.  (Character).  For TYPE = EQUAT the following fields are identification numbers of DEQATN entries.  For TYPE = TABLE the following field is an identification number of a TABLEDi entry.  TYPE is ignored for GENER. </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Required for SPRING or DAMPER </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">IDT </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Identification number of a DEQATN entry for tension if TYPE = EQUAT.  Identification numberof a TABLEDi entry for tension and compressionif TYPE = TABLE. </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Required for SPRING, DAMPER, and GENER </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">IDC </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Identification number of a DEQATN entry for compression if TYPE = EQUAT.  Is ignored for TYPE = TABLE. </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">IDT </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">IDTDU </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Identification number of a DEQATN entry for tension if TYPE = EQUAT.  The DEQATN entry defines the derivative of the force F with respect to the displacement u, for tension u &gt; 0.  For SPRING and GENER only. </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Required if TYPE=EQUAT </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">IDCDU </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Identification number of a DEQATN entry for compression if TYPE = EQUAT.  The DEQATN entry defines the derivative of the force F with respect to the displacement u, for compression u &lt; 0.  For SPRING and GENER only. </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">IDTDU </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">IDTDV </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Identification number of a DEQATN entry for tension if TYPE = EQUAT.  The DEQATN entry defines the derivative of the force F with respect to the velocity v, for tension v &gt; 0.  For DAMPER and GENER only. </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Required if TYPE=EQUAT </p>
                  </td>
               </tr>
               <tr>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">IDCDV </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">Identification number of a DEQATN entry for compression if TYPE = EQUAT.  The DEQATN entry defines the derivative of the force F with respect to the velocity v, for compression v &lt; 0.  For DAMPER and GENER only. </p>
                  </td>
                  <td align="left" colspan="1" rowspan="1" valign="top">
                     <p class="para_td">IDCDT </p>
                  </td>
               </tr>
            </tbody>
         </table><br></div>
      <div class="title_refCategory">Remarks: </div>
      <div class="refCategoryContent">
         <ol type="1" start="1">
            <li><a name="ref87494"></a><p class="para_item">Either the stiffness K or the damping C must be specified. </p>
            </li>
            <li><a name="ref39634"></a><p class="para_item">The damping C and mass M are ignored in static solution sequences. </p>
            </li>
            <li>
               <p class="para_item">The parameters defined on the continuation entries are used in nonlinear solution sequences only. </p>
            </li>
            <li>
               <p class="para_item">The linear parameters K and C are used in all solution sequences unless parameters on continuation entries are defined and a nonlinear solution sequence is used. Then, the parameters K and C are used for initial values in the first iteration of the first load step and the parameters from continuation entries overwrite the linear parameters thereafter.  When SHOCKA, SPRING or GENER are specified, K is overwritten.  When SHOCKA, DAMPER or GENER is specified, C is overwritten. </p>
            </li>
            <li>
               <p class="para_item">PBUSH1D may only be referenced by CBUSH1D elements in the residual structure which do not attach to omitted degrees-of-freedom. </p>
            </li>
            <li>
               <p class="para_item">The continuation entries SHOCKA, SPRING, DAMPER and GENER may be specified in any order. If more than one continuation entry is defined, then the forces of SHOCKA, SPRING, etc. are added.  Multiple continuation entries of the same kind are not allowed, for example, multiple SPRING continuation entries. </p>
            </li>
            <li>
               <p class="para_item">For TYPE = TABLE, values on the TABLEDi entry are for tension and compression. If table values <em>f</em>(<em>u</em>) are provided only for positive values  u &gt; 0, then it is assumed that <em>f</em>(−<em>u</em>) = −<em>f</em>(<em>u</em>). 
               </p>
            </li>
            <li>
               <p class="para_item">For TYPE = EQUAT, the equations for tension and compression can be different. If the identification numbers for compression are left blank, it is assumed that the equation for tension is also valid for compression. </p>
            </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">Only &ldquo;SPRING&rdquo; continuation entry line is supported. Warning is issued for other continuation entry lines. </p>
            </li>
            <li>
               <p class="para_item">Only the following fields are supported: PID, K, C, M, SA, TYPE and IDT in &ldquo;SPRING&rdquo;. Hence, the spring stiffness may be nonlinear but the damping is linear. </p>
            </li>
            <li>
               <p class="para_item">Only TYPE=TABLE (or blank) is supported. Otherwise, a fatal error is issued. </p>
            </li>
         </ol>
      </div>
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