Data Exchange Formats

1
Data Exchange Formats

• DXF
• IGES
• STEP
• Parasolid (kernel)
• Proprietary formats
• CAD/CAE APIs
• NASTRAN BDF
• MARC DECK
• ANSYS DECK

2
Data Exchange - DXF

• DXF is Drawing Interchange File Format defined by
  AutoDesk,Inc., (AutoCAD)
• ASCII and Binary formats
• DXFIN, DXFOUT
• Precision (accuracy) control

3
Data Exchange - DXF

• HEADER SECTION
• TABLES SECTION
• BLOCKS SECTION
• ENTITIES SECTION
• END OF FILE SECTION

4
Data Exchange - DXF

• Multiplicity of groups ( 2 lines)
• Group code and group value

5
Data Exchange
6
DXF

7
Data Exchange - DXF

• Comments section ( 999 comment code)

8
Data Exchange - DXF

• Spline header variables

9
Data Exchange curves
10
Data Exchange

• Attributes

11
Data Exchange

• Periodic and closed are both required to have
  positional continuity
• Periodic has additional requirements ( tangent
  continuity)

12
Data Exchange

• NASTRAN, ANSYS and MARC