An element component is a representation for minor items included in, added to or connecting to or between
elements, which usually are not of interest from the overall building structure viewpoint.
However, these small parts may have vital and load carrying functions within the construction.
These items do not provide any actual space boundaries.
Typical examples of IfcElementComponents include different kinds of fasteners and various accessories.
One or several instances of subtypes of IfcElementComponent should always be accompanied by a defining instance of a respective subtype of IfcElementComponentType. The type object holds shape and material information.
HISTORY New entity in IFC2x2
It is often desirable to model a number of same-shaped element components by means of a single
occurrence object, e.g. several bolts within a connection or a row of reinforcement elements.
In this IFC release, this is possible by means of multiple mapped representation as documented below.
To express the multiplicity of element components also on a higher semantic level,
a Qto_ElementComponentPatternQuantities should be provided via IfcRelDefinesByProperties
and contain the number of pieces which are placed by a single IfcElementComponent instance.
A symbolic representation is defined for a row of components or several rows of
components within a single instance of IfcElementComponent. Such rows or arrays may
contain possibly large numbers of individual pieces. The product definition shape consists of
an IfcShapeRepresentation with the attribute values
- RepresentationIdentifier : 'Row'
- RepresentationType : 'GeometricCurveSet'
and one or several curves as geometric items. The curves represent where reference points of
the pieces are located. For example, such reference points may be at the heads of mechanical fasteners
or at the starting point of the extrusion axis of reinforcement bars. In case of straight components
(bolts, nails, staples, straight reinforcement bars, or similar), the local placement of the
IfcElementComponent shall be located and oriented such that the local z axis is parallel with
the axes of the components. A Qto_ElementComponentPatternQuantities should denote the count
of pieces in the row or array and their spacing.
Common Use Definitions
The following concepts are inherited at supertypes:
Property Sets for Objects
The Property Sets for Objects concept applies to this entity as shown in Table 227.
Table 227 — IfcElementComponent Property Sets for Objects
The Mapped Geometry concept applies to this entity.
The mapped item, IfcMappedItem, should be used if appropriate as it allows for reusing the geometry definition of a type at all occurrences of the same type.
A single instance of a subtype of IfcElementComponent can stand for several
actual element components at once. In this case, the IfcShapeRepresentation
contains as many mapped items as there are element components combined within this
EXAMPLE Figure 238 illustrates multiple components modeled as a single occurrence object (here: IfcFastener)
Figure 238 — Element component mapped representation
Representation identifier and type are the same as in single mapped representation.
The number of mapped items in the representation corresponds with the count of
element components in the IfcElementQuantity.
XSD Specification: <xs:element name="IfcElementComponent" type="ifc:IfcElementComponent" abstract="true" substitutionGroup="ifc:IfcElement" nillable="true"/>
<xs:complexType name="IfcElementComponent" abstract="true">
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