Structural Design
User Guide
Structural Catalogue : Basic Features of the Catalogue
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A Geometry Set, which defines the overall physical shape of the item in terms of a set of 2D and/or 3D basic shapes (known as primitives). A sectional profile is made up of 2D primitives only (which are extruded to form a 3D section in the design model); a joint or a fitting is made up of 3D primitives which define its complete volume. A geometry set can include negative 3D primitives to represent holes.
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Point Set, which defines a number of reference points and directions superimposed on the geometric shape so that individual parts of that shape can be identified and manipulated. These reference points can include p-points, which represent a 1D point position and a direction, and p-lines (or plines), which represent a 2D line and a direction.
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A range of catalogue components with similar overall geometry all reference the same geometry set and point set, so that the amount of data needed to represent all possible items is kept to a minimum. The dimensions of the items are not fixed in the catalogue but are expressed in terms of design parameters. Values are allocated to these parameterised dimensions when the item is used in a specific part of the design model: they may either be set explicitly or derived from associated dimensions of other design components to which the item is to be connected.
