The MIDH field represents the Helius PFA material identification number found in the HPFAMatDB.xml file in the materials directory. When Helius PFA is installed for Autodesk Inventor Nastran, an HPFAMatDB.xml file is created in two locations: the %APPDATA%\Autodesk\Helius PFA 2018\Materials folder and the AUTODESK_DIR\Materials folder (C:\Program Files\Autodesk\Helius PFA 2018\Materials for example). The purpose of this file is to link the Helius PFA material identification number (MIDH) with the name of a material stored in the Helius PFA Materials Database (this is the %APPDATA%\Autodesk\Helius PFA 2018\Materials directory).
The material identification numbers for the composite materials that come with the product are already included in this file. If a new material file is created using Composite Material Manager, the HPFAMatDB.xml file is automatically updated to include the new material and is assigned a material MIDH number. However, if the material files are manually copied and edited, the HPFAMatDB.xml file must be updated to include the new link between the material identification number (MIDH) and the name of the newly created composite material. If the HPFAMatDB.xml file is opened using a text editor or internet browser, the contents will look similar to the following (if opened with a text editor):
<?xml version="1.0"?>
<HPFAMatDB>
<Material id="9001" name="AS4-3501-6"/>
<Material id="9002" name="AS4_3502"/>
<Material id="9003" name="AS4_8552"/>
<Material id="9004" name="AS_Epoxy1"/>
<Material id="9005" name="Eglass21xK43Gevetex-LY556"/>
<Material id="9006" name="HTS150_TC250"/>
<Material id="9007" name="IM7-977-2"/>
<Material id="9008" name="IM7_5250-4"/>
<Material id="9009" name="IM7_8551"/>
<Material id="9010" name="IM7_8552"/>
<Material id="9011" name="IM7_977-3"/>
<Material id="9012" name="S2\_Glass\_Epoxy2"/>
<Material id="9013" name="SilEglass1200tex-MY750"/>
<Material id="9014" name="T300-BSL914C"/>
<Material id="9015" name="T300_976"/>
<Material id="9016" name="T300_PR319"/>
<Material id="9017" name="T800H_3900-2"/>
</HPFAMatDB>To add a link between a newly created material file and a Helius PFA material identification number (MIDH), copy the format of the existing file to add an additional line that links the two items. For example, if the newly created material file was saved as example_composite_material, the file would be modified as:
<?xml version="1.0"?>
<HPFAMatDB>
<Material id="9001" name="AS4-3501-6"/>
<Material id="9002" name="AS4_3502"/>
<Material id="9003" name="AS4_8552"/>
<Material id="9004" name="AS_Epoxy1"/>
<Material id="9005" name="Eglass21xK43Gevetex-LY556"/>
<Material id="9006" name="HTS150_TC250"/>
<Material id="9007" name="IM7-977-2"/>
<Material id="9008" name="IM7_5250-4"/>
<Material id="9009" name="IM7_8551"/>
<Material id="9010" name="IM7_8552"/>
<Material id="9011" name="IM7_977-3"/>
<Material id="9012" name="S2\_Glass\_Epoxy2"/>
<Material id="9013" name="SilEglass1200tex-MY750"/>
<Material id="9014" name="T300-BSL914C"/>
<Material id="9015" name="T300_976"/>
<Material id="9016" name="T300_PR319"/>
<Material id="9017" name="T800H_3900-2"/>
<Material id="9018" name="example\_composite\_material"/>
</HPFAMatDB>The value 9018 would be used in the MIDH field in the MATPFA entry telling Helius PFA to use the material "example_composite_material".