IfcCShapeProfileDef

Semantic definitions at the entity

Entity definition

The IfcCShapeProfileDef defines a section profile that provides the defining parameters of a C-shaped section to be used by the swept area solid. This section is typically produced by cold forming steel. 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:

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 C-shape profile definition

Attribute definitions

#	Attribute	Type	Cardinality	Description	A
4	Depth	IfcPositiveLengthMeasure	[1:1]	Profile depth, see illustration above (= h).	X
5	Width	IfcPositiveLengthMeasure	[1:1]	Profile width, see illustration above (= b).	X
6	WallThickness	IfcPositiveLengthMeasure	[1:1]	Constant wall thickness of profile (= ts).	X
7	Girth	IfcPositiveLengthMeasure	[1:1]	Lengths of girth, see illustration above (= c).	X
8	InternalFilletRadius	-		This attribute is out of scope for this model view definition and shall not be set.
9	CentreOfGravityInX	-		This attribute is out of scope for this model view definition and shall not be set.

Formal Propositions

Rule	Description
WR1	The girth shall be smaller than half of the depth.
WR2	If the value for InternalFilletRadius is given, it shall be smaller than half of the Depth and half of the Width.
WR3	The WallThickness shall be smaller than half of the Width and half of the Depth.

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	A
IfcProfileDef
1	ProfileType	IfcProfileTypeEnum	[1:1]	Defines the type of geometry into which this profile definition shall be resolved, either a curve or a surface area. In case of curve the profile should be referenced by a swept surface, in case of area the profile should be referenced by a swept area solid.	X
2	ProfileName	-		This attribute is out of scope for this model view definition and shall not be set.
IfcParameterizedProfileDef
3	Position	IfcAxis2Placement2D	[1:1]	Position coordinate system of the parameterized profile definition.	X
IfcCShapeProfileDef
4	Depth	IfcPositiveLengthMeasure	[1:1]	Profile depth, see illustration above (= h).	X
5	Width	IfcPositiveLengthMeasure	[1:1]	Profile width, see illustration above (= b).	X
6	WallThickness	IfcPositiveLengthMeasure	[1:1]	Constant wall thickness of profile (= ts).	X
7	Girth	IfcPositiveLengthMeasure	[1:1]	Lengths of girth, see illustration above (= c).	X
8	InternalFilletRadius	-		This attribute is out of scope for this model view definition and shall not be set.
9	CentreOfGravityInX	-		This attribute is out of scope for this model view definition and shall not be set.

Formal representations

XSD Specification

 <xs:element name="IfcCShapeProfileDef" type="ifc:IfcCShapeProfileDef" substitutionGroup="ifc:IfcParameterizedProfileDef" nillable="true"/>

 <xs:complexType name="IfcCShapeProfileDef">

  <xs:complexContent>

   <xs:extension base="ifc:IfcParameterizedProfileDef">

    <xs:attribute name="Depth" type="ifc:IfcPositiveLengthMeasure" use="optional"/>

    <xs:attribute name="Width" type="ifc:IfcPositiveLengthMeasure" use="optional"/>

    <xs:attribute name="WallThickness" type="ifc:IfcPositiveLengthMeasure" use="optional"/>

    <xs:attribute name="Girth" type="ifc:IfcPositiveLengthMeasure" use="optional"/>

   </xs:extension>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


ENTITY IfcCShapeProfileDef

 SUBTYPE OF (IfcParameterizedProfileDef);

  Depth : IfcPositiveLengthMeasure;

  Width : IfcPositiveLengthMeasure;

  WallThickness : IfcPositiveLengthMeasure;

  Girth : IfcPositiveLengthMeasure;

  InternalFilletRadius : OPTIONAL IfcStrippedOptional;

  CentreOfGravityInX : OPTIONAL IfcStrippedOptional;

 WHERE

  WR1 : Girth < (Depth / 2.);
  WR2 : NOT(EXISTS(InternalFilletRadius)) OR
((InternalFilletRadius <= Width/2.) AND (InternalFilletRadius <= Depth/2.));
  WR3 : (WallThickness < Width/2.) AND (WallThickness < Depth/2.);
END_ENTITY;

 EXPRESS-G diagram