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IfcAsymmetricIShapeProfileDef

Definition from IAI: The IfcAsymmetricIShapeProfileDef defines a section profile that provides the defining parameters of an asymmetric I-shaped section to be used by the swept area solid. The bottom flange is always wider than the top flange. Its parameters and orientation relative to the position coordinate system are according to the following illustration. The centre of the position coordinate system is in the profiles centre of the gravity bounding box.

The centre of gravity, if given, is located in x direction within the center of the bounding box, and in y-direction along the negative y axis, the offset value is given by the offset parameter CentreOfGravityInY.

NOTE: The inherited attributes are used to define:
HISTORY  New entity in Release IFC2x Edition 2.

IFC2x Edition 3 CHANGE  All profile origins are now in the center of the bounding box. The attribute CentreOfGravityInY has been made OPTIONAL. Upward compatibility for file based exchange is guaranteed.

Illustration:

asymmetric I shape profile

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.

Table: Parameters of asymmetric I-shaped section definition

EXPRESS specification:

ENTITY IfcAsymmetricIShapeProfileDef
SUBTYPE OF ( IfcIShapeProfileDef);
TopFlangeWidth  :  IfcPositiveLengthMeasure;
TopFlangeThickness  :  OPTIONAL IfcPositiveLengthMeasure;
TopFlangeFilletRadius  :  OPTIONAL IfcPositiveLengthMeasure;
CentreOfGravityInY  :  OPTIONAL IfcPositiveLengthMeasure;
END_ENTITY;

Attribute definitions:

TopFlangeWidth  :  Extent of the top flange, defined parallel to the x axis of the position coordinate system.
TopFlangeThickness  :  Flange thickness of the top flange of the I-shape. If given, the upper and the lower flanges can have different thicknesses. If not given, the value of the inherited FlangeThickness attribute applies to both, the top and bottom flange thickness.
TopFlangeFilletRadius  :  The fillet between the web and the top flange of the I-shape. If given, the fillet between upper and the lower flanges and the web can be different. If not given, the value of the inherited FilletRadius attribute applies to both, the top and bottom fillet. If the inherited FilletRadius is not given either, no filler is applied.
CentreOfGravityInY  :  Location of centre of gravity along the y axis measured from the center of the bounding box.
IFC2x Edition 2 Addendum 2 CHANGE The attribute CentreOfGravityInY has been made optional. Upward compatibility for file based exchange is guaranteed.

Inheritance graph

ENTITY IfcAsymmetricIShapeProfileDef;
ENTITY IfcProfileDef;
ProfileType  :  IfcProfileTypeEnum;
ProfileName  :  OPTIONAL IfcLabel;
ENTITY IfcParameterizedProfileDef;
Position  :  IfcAxis2Placement2D;
ENTITY IfcIShapeProfileDef;
OverallWidth  :  IfcPositiveLengthMeasure;
OverallDepth  :  IfcPositiveLengthMeasure;
WebThickness  :  IfcPositiveLengthMeasure;
FlangeThickness  :  IfcPositiveLengthMeasure;
FilletRadius  :  OPTIONAL IfcPositiveLengthMeasure;
ENTITY IfcAsymmetricIShapeProfileDef;
TopFlangeWidth  :  IfcPositiveLengthMeasure;
TopFlangeThickness  :  OPTIONAL IfcPositiveLengthMeasure;
TopFlangeFilletRadius  :  OPTIONAL IfcPositiveLengthMeasure;
CentreOfGravityInY  :  OPTIONAL IfcPositiveLengthMeasure;
END_ENTITY;