Curve mesh parameters definition
- @CURVE_MESH_PARAMETERS_DEFINITION {
- @CURVE_MESH_PARAMETERS_NAME {MeshCurvName} {
- @NUMBER_OF_ELEMENTS {N_{el}}
- @ORDER_OF_ELEMENTS {o_{el}}
- @ETA_VALUE { η_{1}, η_{2},... η_{n}}
- @COMMENTS {CommentText}
- }
- }
Notes
- When creating a finite element discretization of the multibody system, structural components will be broken into several finite elements. Structural components can be defined along a curve, 1-D components such as beam and cables), or on a surface, 2-D components such as plates and shells. This section provides the parameters that will control the meshing process. For 1-D components, these parameters fully define the mesh. For 2-D components, the mesh is defined by the parameters associated with two adjacent curves of the surface.
- The mesh is defined by the number of elements along the curve and their order. The curve will be broken into N_{el} elements, each of order o_{el}.
- If o_{el} = 1, the corresponding elements will use linear shape functions; i.e. the element has two nodes.
- If o_{el} = 2, parabolic shape functions are used; i.e. the element has three nodes.
- If o_{el} = 3, cubic shape functions are used; i.e. the element has four nodes.
- In general, the curve will be divided into N_{el} elements of equal size. However, if element of unequal size are desired, the size of each element can be specified with their optional @ETA_VALUE. N_{el} + 1 entries must appear, the first entry must be η_{1} = 0.0, the last η_{n} = 1.0, and the non-decreasing intermediate values determine the size of the various elements. The η values correspond to the parameterization of the curve inherent to its NURBS representation.
- It is possible to attach comments to the definition of the object; these comments have no effect on its definition.
For example, the discretization of a beam with the following mesh parameters, N_{el} = 4 and o_{el} = 3, will feature a total of 4 × 3 + 1 = 13 nodes. Since the beam has six degrees of freedom per node, the discretization involves 13 × 6 = 78 degrees of freedom.