Curves and Surface Primitives

Curve is used here as a generic term designating various kinds of lines, fro m straight lines to parametric curves. Curves are used as the most basic objects defining the geometry of the finite element model. The following types of curves are supported in VisualFEA. 

In VisualFEA, curves are used extensively for mesh generation, in various forms as follows: 

Surface primitive implies analytic or parametric surface defined as a constraint for mesh generation, and is termed here as such to distinguish it from surface mesh. The following types of curves are supported in VisualFEA.

The surface primitives may be used as a mapping space or bounding surface for mesh generation. They may also be used to create curves in 3-dimensional space by their intersection. The curves and surface primitives are created interactively by inputting control points using either mouse or keyboard. Once created, curves or surface primitives can be modified later. General editing commands such as coping, duplicating, deleting are available for them. They can also be processed by various operations such as intersecting, linking, filleting and projecting.

Curves and surface primitives are meaningful as parts of a geometric model for finite element analysis. They are not directly involved in actual processing of finite element analysis, but are used as modeling objects defining nodes and elements. Curve division is used for creation of line elements as well as for controlling the mesh density.