The SEDRIS Data Representation Model
APPENDIX A - Classes
Finite Element Mesh

Class Name: Finite Element Mesh

Superclass - <Primitive Geometry>

Subclasses

This DRM class is concrete and has no subclasses.

Definition

An instance of this DRM class specifies a tessellation of a surface into mesh faces or of a solid into solid elements. Additional data may be associated with each vertex, mesh face, and/or solid element.

A <Finite Element Mesh> instance is comprised of:

  1. an ordered list of <Vertex> components where the position in the ordering forms an index number to each <Vertex> component,
  2. a <Mesh Face Table> component that defines the mesh faces in terms of the index numbers of the <Vertex> components, and
  3. optionally, <Property Table> components providing additional data (details given below).

Knowledge of which vertices form a mesh face (or solid) is important for various computations, such as interpolation.

<Property Table> components are optional. When present, they are used to define solid elements and to associate data with <Vertex> instances, mesh faces, or solid elements.

Primary Page in DRM Diagram:

Secondary Pages in DRM Diagram:

Example

  1. In support of a rain run-off computational model, a ground surface area is triangulated. At each triangle vertex, the gradient, porosity, flow resistance, water capacity, and rain rate are measured.

    This environmental data is represented in a <Finite Element Mesh> instance by:

    1. an ordered list of <Vertex> components (one for each triangle vertex),
    2. a <Mesh Face Table> component to define the triangles,
    3. a <Property Table> component classified as ECC_MESH_FACE_PROPERTY_SET for the gradient data, and
    4. a <Property Table> component classified as ECC_MESH_NODE_PROPERTY_SET for the remaining properties.

FAQs

What is the difference between a surface and a solid <Finite Element Mesh> instance?

Surface mesh does not have any <Property Table> instances classified as either ECC_MESH_SOLID_SET or ECC_MESH_SOLID_PROPERTY_SET, but may have surface topology in its <Mesh Face Table> component.

A solid mesh shall have a <Property Table> component classified as ECC_MESH_SOLID_SET, may have a <Property Table> component classified as ECC_MESH_SOLID_PROPERTY_SET, and does not have surface topology in its <Mesh Face Table> component.

Where can users obtain further information about <Finite Element Mesh> instances and their associated <Data Table> instances?

See P4V6 of the SEDRIS Documentation Set.

Constraints

Composed of (two-way) (inherited)

Composed of (two-way)

Composed of (two-way metadata) (inherited)

Component of (two-way) (inherited)

Inherited Field Elements

This class has no inherited field elements.

Notes

Composed of Notes


Union_Of_Primitive_Geometry

A <Primitive Geometry> instance P has a <Union Of Primitive Geometry> component only when P can be decomposed into nested <Primitive Geometry> instances.

EXAMPLE  A <Polygon> instance can be decomposed into multiple <Polygon> instances representing subfaces.


Vertex

Since a <Vertex> instance shall have a <Location> component, an enumerated collection of <Location> instances is also provided.


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Last updated: July 26, 2006 Copyright © 2006 SEDRIS