Acknowledgements

What is a pyramid?

• IRIS Explorer data type
• Hierarchy of elements in layers
• Connections between elements in adjacent layers
• Lattice used to store data and coords for elements in a layer
• Used for hierachical data structures such as finite element (FE) data

Pyramids and FE data

• Layers contain elements of different dimensionality
• Hierarchy defines FE grid as
  • objects made up of
  • cells made up of
  • faces made up of
  • edges made up of
  • vertices

Storing element data in layers

• Storage for data and coords for
  • vertices in base lattice
  • edges in layer[0] lattice
  • faces in layer[1] lattice
  • cells in layer[2] lattice
  • objects in layer[3] lattice
• ...

What's new?

• Currently, most modules only use data in the base lattice
• Modules are now being updated to use data at other levels as well

New ReadAVSucd

• Reads files in AVS unstructured cell datatype format
  • vertex coords
  • cell connectivity
  • vertex data
  • cell data new
• No coords for cell data in this format, so generate them from vertex coords

New PyrToGeom

• Creates geometry from pyramid as
  • vertices (points)
  • edges (vectors)
  • faces (polygons)
  • cells (external polygons)
• Geometry coloured according to
  • data in base lattice, or
  • data in level lattice, if present new

Examples

FE data (1)

• FE calculation on machine part
• Calculates
  • Displacements at nodes
  • Velocities in cells
• Data read into pyramid using ReadAVSucd
• PyrToLat extracts lattice from pyramid layer
• VectorDisplay displays vectors

FE data (2)

• FE calculation on cylinder segment
• Calculates
  • Temperature at nodes (vertices)
  • Stresses in elements (cells)
• PyrToGeom creates geometry and colours it according to
  • vertex data, or
  • cell data

FE data (3)

• FE calculation on blade
• 5500 nodes, 3000 cells
• Calculates
  • Temperature at nodes
  • Centroid pressure at cells
• PyrToGeom creates geometry and colours it according to
  • vertex data, or
  • cell data
  

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  Last modified: Mon Aug 5 14:50:24 1996
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  © The Numerical Algorithms Group Ltd, Oxford UK, 1996.