Represent Profile Rectangle

Overview

Identifies the information requirements for the provision of a rectangle profile.
Within this functional part, a rectangle profile may be used to represent:

a solid rectangle (equivalent to a representation that would be used for a rectangular cross section bar or solid timber piece),
a thin shell rectangle (equivalent to the cross section of a rectangular duct)
a thin shell rounded rectangle (equivalent to the cross section of a flat oval duct)
a hollow rectangle (equivalent to a representation that would be used for a rectangular or flat oval shape with a known wall thickness).
A rectangle is a profile definition that may be used by a swept surface geometry representation or by a swept area solid representation. A rectangle profile is specified by its X and Y dimension attributes, optional wall thickness attribute and optional corner radius attribute. It is placed within the 2D position coordinate system, established by the Position attribute.
In the description below, the parameters for a solid or thin shell profile are attributes of IfcRectangleProfileDef whilst the parameters for a hollow profile are attributes of IfcRectangleHollowProfileDef and for a rounded rectangle profile are attributes of IfcRoundedRectangleProfileDef.
Note that the limits of a rectangle with rounded edges are a rectangle (for radius = 0) and a circle (for X = Y and radius = 0.5 * X). However, the circle limit can be approached but not attained since the value of the X and Y dimensions is a positive length measure which must be greater than 0.

Results

Specification of the parameters of a rectangle profile.

Description	Entity/Pset/Functional Part	MAN	REC	OPT
Set the position from which the parameters of the profile are determined. Note that the position is located centrically within the rectangle i.e. at the junction of the diagonals of the rectangle.	IfcRectangleProfileDef.Position::fp_place (2D) OR IfcRectangleHollowProfileDef.Position::fp_place (2D) OR IfcRoundedRectangleProfileDef.Position::fp_place (2D)
Set the value of the X and Y dimensions of the rectangle. For a hollow circle profile, this value defines the external radius	IfcRectangleProfileDef.XDim::IfcPositiveLengthMeasure IfcRectangleProfileDef.YDim::IfcPositiveLengthMeasure OR IfcRectangleHollowProfileDef.XDim::IfcPositiveLengthMeasure IfcRectangleHollowProfileDef.YDim ::IfcPositiveLengthMeasure OR IfcRoundedRectangleProfileDef.XDim::IfcPositiveLengthMeasure IfcRoundedRectangleProfileDef.YDim::IfcPositiveLengthMeasure
For a hollow rectangle profile, set the value of the wall thickness. This is the value by which the inner rectangle profile is offset from the outer rectangle profile. This value should be asserted for rectangular pipe/tube representations but does not need to be asserted for solid or thin shell representations. The wall thickness value must be set so that it is less than 0.5. the smaller of the X and Y dimensions of the rectangle.*	IfcRectangleHollowProfileDef.WallThickness::IfcPositiveLengthMeasure
For a hollow rectangle, values for the inner and outer fillet radius may be set if appropriate. If the values are not asserted, this means that there is no rounding of the corners of the hollow rectangle. Where values are asserted, the impact is to create a hollow flat oval shape. The radius values must be set so that the corner radius it is less than 0.5. the smaller of the X and Y dimensions of the rectangle.*	IfcRectangleHollowProfileDef.InnerFilletRadius::IfcPositiveLengthMeasure IfcRectangleHollowProfileDef.OuterFilletRadius::IfcPositiveLengthMeasure
For a rounded rectangle, set the value of the rounding radius applied at each corner of the rectangle	IfcRoundedRectangleProfileDef.RoundingRadius::IfcPositiveLengthMeasure
Set the value of the profile type. The setting of this value defines whether a geometric representation derived from the profile is to be a swept surface or a swept solid. If it is to be a swept surface then the value should be set to CURVE. If the representation if to be a swept solid, then the value should be set to AREA. Note that for a hollow rectangle profile, the provision of parameters leaves it open to the software author as to how to apply the parameters (whether as two curves or as two solids) and whether Boolean operators are to be applied for presentation purposes).	IfcRectangleProfileDef.ProfileType::IfcProfileTypeEnum OR IfcRectangleHollowProfileDef.ProfileType::IfcProfileTypeEnum OR IfcRoundedRectangleProfileDef.ProfileType::IfcProfileTypeEnum

IFC Entities Required

IfcParameterizedProfileDef
IfcProfileDef
IfcRectangleProfileDef
IfcRectangleHollowProfileDef
IfcRoundedRectangleProfileDef

IFC Datatypes Required

IfcLabel
IfcLengthMeasure
IfcPositiveLengthMeasure
IfcProfileTypeEnum

IFC Functions Required

-

IDM Functional Parts Required

fp_place (2D)

EXPRESS-G

EXPRESS Schema

SCHEMA FP_REPRESENT_PROFILE_RECTANGLE;

  TYPE IfcLabel = STRING;
  END_TYPE;

  TYPE IfcLengthMeasure = REAL;
  END_TYPE;

  TYPE IfcPositiveLengthMeasure = IfcLengthMeasure;
    WHERE
      WR1 : SELF > 0;
  END_TYPE;

  TYPE IfcProfileTypeEnum = ENUMERATION OF
    (CURVE,
     AREA);
  END_TYPE;

  ENTITY IfcProfileDef
    ABSTRACT SUPERTYPE;
      ProfileType : IfcProfileTypeEnum;
      ProfileName : OPTIONAL IfcLabel;
  END_ENTITY;

  ENTITY IfcParameterizedProfileDef
    ABSTRACT SUPERTYPE
    SUBTYPE OF(IfcProfileDef);
      Position : fp_place;
  END_ENTITY;

  ENTITY IfcRectangleProfileDef
    SUPERTYPE OF (ONEOF(IfcRectangleHollowProfileDef, IfcRoundedRectangleProfileDef))
    SUBTYPE OF(IfcParameterizedProfileDef);
      XDim : IfcPositiveLengthMeasure;
      YDim : IfcPositiveLengthMeasure;
  END_ENTITY;

  ENTITY IfcRectangleHollowProfileDef
    SUBTYPE OF(IfcRectangleProfileDef);
      WallThickness     : IfcPositiveLengthMeasure;
      InnerFilletRadius : OPTIONAL IfcPositiveLengthMeasure;
      OuterFilletRadius : OPTIONAL IfcPositiveLengthMeasure;
    WHERE
      WR1 : (WallThickness < (SELF\IfcRectangleProfileDef.XDim / 2)) AND 
            (WallThickness < (SELF\IfcRectangleProfileDef.YDim / 2));
      WR2 : NOT(EXISTS(OuterFilletRadius)) OR 
            ((OuterFilletRadius <= (SELF\IfcRectangleProfileDef.XDim / 2)) AND 
            (OuterFilletRadius <= (SELF\IfcRectangleProfileDef.YDim / 2)));
      WR3 : NOT(EXISTS(InnerFilletRadius)) OR 
            ((InnerFilletRadius <= (SELF\IfcRectangleProfileDef.XDim / 2 - WallThickness)) AND 
            (InnerFilletRadius <= (SELF\IfcRectangleProfileDef.YDim / 2 - WallThickness)));
  END_ENTITY;

  ENTITY IfcRoundedRectangleProfileDef
    SUBTYPE OF(IfcRectangleProfileDef);
      RoundingRadius : IfcPositiveLengthMeasure;
    WHERE
      WR21 : ((RoundingRadius <= (SELF\IfcRectangleProfileDef.XDim/2)) AND 
             (RoundingRadius <= (SELF\IfcRectangleProfileDef.YDim/2)));
  END_ENTITY;

  ENTITY fp_place;
  END_ENTITY;

END_SCHEMA;

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