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IfcUShapeProfileDef

Definition from IAI: The IfcUShapeProfileDef defines a section profile that provides the defining parameters of a U-shape (channel) section to be used by the swept area solid. 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 y direction within the center of the bounding box, and in x-direction along the negative x axis, the offset value is given by the offset parameter CentreOfGravityInX.

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 CentreOfGravityInX has been made OPTIONAL. Upward compatibility for file based exchange is guaranteed.

Illustration:

U-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 U-shape profile definition

EXPRESS specification:

ENTITY IfcUShapeProfileDef
SUBTYPE OF ( IfcParameterizedProfileDef);
Depth  :  IfcPositiveLengthMeasure;
FlangeWidth  :  IfcPositiveLengthMeasure;
WebThickness  :  IfcPositiveLengthMeasure;
FlangeThickness  :  IfcPositiveLengthMeasure;
FilletRadius  :  OPTIONAL IfcPositiveLengthMeasure;
EdgeRadius  :  OPTIONAL IfcPositiveLengthMeasure;
FlangeSlope  :  OPTIONAL IfcPlaneAngleMeasure;
CentreOfGravityInX  :  OPTIONAL IfcPositiveLengthMeasure;
WHERE
WR21  :  FlangeThickness < (Depth / 2.);
WR22  :  WebThickness < FlangeWidth;
END_ENTITY;

Attribute definitions:

Depth  :  Web lengths, see illustration above (= h).
FlangeWidth  :  Flange lengths, see illustration above (= b).
WebThickness  :  Constant wall thickness of web (= ts).
FlangeThickness  :  Constant wall thickness of flange (= tg).
FilletRadius  :  Fillet radius according the above illustration (= r1). If it is not given, zero is assumed.
EdgeRadius  :  Edge radius according the above illustration (= r2). If it is not given, zero is assumed.
FlangeSlope  :  Slope of flange of the profile. If it is not given, zero is assumed.
CentreOfGravityInX  :  Location of centre of gravity along the x axis measured from the center of the bounding box.
IFC2x Edition 2 Addendum 2 CHANGE The attribute CentreOfGravityInX has been made optional. Upward compatibility for file based exchange is guaranteed.

Formal Propositions:

WR21  :  The flange thickness shall be smaller than half of the depth.
WR22  :  The web thickness shall be smaller than the flange width.

Inheritance graph

ENTITY IfcUShapeProfileDef;
ENTITY IfcProfileDef;
ProfileType  :  IfcProfileTypeEnum;
ProfileName  :  OPTIONAL IfcLabel;
ENTITY IfcParameterizedProfileDef;
Position  :  IfcAxis2Placement2D;
ENTITY IfcUShapeProfileDef;
Depth  :  IfcPositiveLengthMeasure;
FlangeWidth  :  IfcPositiveLengthMeasure;
WebThickness  :  IfcPositiveLengthMeasure;
FlangeThickness  :  IfcPositiveLengthMeasure;
FilletRadius  :  OPTIONAL IfcPositiveLengthMeasure;
EdgeRadius  :  OPTIONAL IfcPositiveLengthMeasure;
FlangeSlope  :  OPTIONAL IfcPlaneAngleMeasure;
CentreOfGravityInX  :  OPTIONAL IfcPositiveLengthMeasure;
END_ENTITY;