Reading Material Points from a Previous Simulation

Sometimes it is useful to run a simulation, output the material point locations, and them use those settings for a new MPM simulation. One approach is to extract all material point locations to an XML file using the ExtractMPM tool, and then input that file to a new commands file. The process is:

1. Run an MPM simulation
2. Select an archive time and use ExtractMPM to extract particle data to an XML file. A typical command would be:

   ExtractMPM -Xh -q mass -o particles Archive.1843
   

   where Archive.1843 is desired time archive containing material point locations. The points will be written to an XML file called particles.xml. The output file will have one <PointList block with one<mp>element for each material point. See the ExtractMPM tool documentation for more details on an XML extraction.
3. Finally, include this saved file in another commands file using an XML entity reference. First, define the path to the new file using an [[Entity Command|Entity\\ command such as:

   Entity mpfile,particles.xml
   

   where its value is a relative path to the file with the particle locations. In scripted files, the entity is defined in the file's DOCTYPE element such as:

   <!DOCTYPE JANFEAInput SYSTEM '/full path to/NairnMPM.dtd'
   [   <!ENTITY mpfile SYSTEM "pointlist.xml">
   ]>
   

   Then, include that file in the section that defines material points using:

   XMLData,MaterialPoint
      &mpfile;
   EndXMLData
   

   In XML files, the file is include in the <MaterialPoints> element using

   <MaterialPoints>
      &mpfile;
   </MaterialPoints>