A NASTRAN file contains a tria/quad face boundary surface grid and (optionally) a polyhedral element volume grid. See NASTRAN related documentation available from other sources for more information. The following types are supported.
GRID* : grid coordinates in long format GRID : grid coordinates CTRIA3 : 3-node tria surface faces CQUAD4 : 4-node quad surface faces CHEXA : 8-node hexahedral elements CPENTA : 5-node pentahedral elements (node 5 equal to node 6) CPENTA : 6-node pentahedral elements CTETRA : 4-node tetrahedral elements
The optional boundary reconnection, boundary condition, initial normal spacing, and boundary-layer thickness data are supported using the following comment lines. This data is only used with boundary surface grids.
$Initial_Normal_Spacing #.# : initial normal spacing one line for each surface node in sequential order $BL_Thickness #.# : BL thickness one line for each surface node in sequential order $Surf_Grid_BC_Flag # : surface grid boundary condition flag one line for each surface face in sequential order with data for surface trias listed first and then data for quads $Surf_Reconnection_Flag # : surface reconnection flag one line for each surface face in sequential order with data for surface trias listed first and then data for quads
The optional number of boundary-layer elements is supported using the following comment line. This data is only used with volume grids.
$Number_of_BL_Elements # : number of BL elements
ASCII formatted is the only file format supported for NASTRAN type grid files.