When creating profile-related symbol geometry, key points can be used for many purposes in geometry construction. Profile symbols are used in the Molded Forms task.
Key points are:
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Standard across all types of profile symbols.
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Internal to the symbol, but are associated with symbol representations that are exposed externally to the catalog.
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Located on a geometric element (for example, an edge on the web, or the mid axis) or at the intersection of two geometric elements (for example, at the intersection of a web edge and a flange edge).
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Defined on an idealized profile shape (that is, without any fillets or radii).
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Constrained to profile geometry.
Multiple point names can be assigned to a key point, with each point name serving a different purpose.
Members in the Structure task use an equivalent point system called cardinal points. The numbering convention for cardinal points differs from key points, as described below.
Key Point Numbering Conventions
Key points are numbered consistently among all types of profile cross-sections without regard to the number of geometric elements. This assures consistent behavior in the software when changing cross-sections of an existing profile system. As a result, some points are coincident on some cross-sections. Key point numbering is based on an I-beam profile because it is the most complex shape. Numbering for other profiles is derived from the I-beam.
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I-beam
Includes rolled and built-up cross-sections. |
S-beam
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T
Includes T and I-to-T. Midpoint is from top of flange. |
Fabricated T
Midpoint is from bottom of flange. |
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S-T
Midpoint is from top of flange. |
Angle Midpoint is from top of flange. |
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Fabricated angles
Midpoint is from top of flange. |
Midpoint is from bottom of flange. |
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Channel
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S-channel
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Flat bar
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Bulb
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Pipe
Includes pipe, tube, and round bar. |
Rectangular tube
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Half-round |
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Cardinal Point Numbering Conventions
A cardinal point defines the location where the software displays a member cross-section. There are 15 cardinal points definable for a member cross-section symbol, but only one can be used at a time when the member is placed. Each cardinal point has a number and a name.
The local y-axis of the member and the center-of-gravity point of the section define load points 11 and 14. The local z-axis of the member and the center-of-gravity point of the section define load points 12 and 13. The location of points 10 (center-of-gravity) and 15 (shear center) depend on the section shape.
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If you want different text descriptions than what is shown for cardinal points, they must be defined on the CrossSectionCardinalPoints sheet of the AllCodeLists.xls workbook, and bulkloaded into the catalog. Only the text descriptions can be modified; the numeric values and their locations are hard-coded. For more information, see the Reference Data Guide.