IfcIShapeProfileDef
Definition
from IAI: The IfcIShapeProfileDef
defines a section profile that provides the defining parameters of a
symmetrical 'I' section to be used by the swept surface geometry or the
swept area solid. The I-shape profile has values for its overall depth,
width and its web and flange thickness. Additionally a fillet radius
may be given. It represents a I-section that is symmetrical about its
major and minor axes; and that has both top and bottom flanges being
equal and centred on the web.
HISTORY: New entity
in IFC Release 2x.
Illustration:
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Position
The parameterized
profile defines its own position coordinate system.
The underlying
coordinate system is defined by the swept area solid
that uses the profile definition. It is the xy plane of:
- IfcSweptAreaSolid.Position
by using offsets of the position location, the parameterized profile
can be positioned centric (using x,y offsets = 0.), or at any position
relative to the profile. Explicit coordinate offsets are used to define
cardinal points (e.g. upper-left bound).
Parameter
The parameterized profile
is defined by a set of parameter attributes, see attribute definition
below.
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Note:
The black coordinate axes show the
underlying coordinate system of the swept surface or swept area solid |
Position
The profile is inserted into the underlying
coordinate system of the swept area solid by using the Position
attribute. In this example (cardinal point of lower left corner) the
attribute values of IfcAxis2Placement2D
are:
Location
= IfcCartesianPoint(<1/2
OverallWidth>,<1/2 OverallDepth>)
RefDirection = NIL (defaults to 1.,0.)
Parameter
If the FilletRadius
is given, it is equally applied to all four corners created by the web
and flanges.
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Table: Parameter of the I-shape profile definition
EXPRESS specification:
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| WR1
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FlangeThickness < (OverallDepth / 2.);
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| WR2
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WebThickness < OverallWidth;
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| WR3
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NOT(EXISTS(FilletRadius)) OR
((FilletRadius <= (OverallWidth - WebThickness)/2.) AND
(FilletRadius <= (OverallDepth - (2. * FlangeThickness))/2.));
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Attribute definitions:
| OverallWidth
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Total extent of the width, defined parallel to the x axis of the position coordinate system.
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| OverallDepth
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Total extent of the depth, defined parallel to the y axis of the position coordinate system.
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| WebThickness
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Thickness of the web of the I-shape. The web is centred on the x-axis and the y-axis of the position
coordinate system.
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| FlangeThickness
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Flange thickness of the I-shape. Both, the upper and the lower flanges have the same thickness and they
are centred on the y-axis of the position coordinate system.
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| FilletRadius
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The fillet between the web and the flange, if not given, zero is assumed.
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Formal Propositions:
| WR1
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The thickness of the flange shall be less than half of the overall depth.
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| WR2
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The web thickness shall be less then the overall width.
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| WR3
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The FilletRadius, if given, should be within the range of allowed values.
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Inheritance graph
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| ENTITY IfcIShapeProfileDef;
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