IfcMaterialDefinition

Item	SPF	XML	Change	Description
IFC2x3 to IFC4
IfcMaterialDefinition			ADDED

Semantic definitions at the entity

Entity definition

IfcMaterialDefinition is a general supertype for all material related information items in IFC that have common material related properties that may include association of material with some shape parameters or assignments to identified parts of a component.

There are three ways of assigning materials to a single component or multiple components; they are characterized as:

by layer - assigning a material to a layer with constant thickness
by profile - assigning a material to a profile with a constant of varying shape along an extrusion
by constituents - assigning a material to an identified part of a component shape; the identification is by a keyword rather than by a shape parameter

Each instantiable subtype of IfcMaterialDefinition may have material properties assigned, or have an external classification of its definition. It can be assigned to either a subtype of IfcElement, or a subtype of IfcElementType by using the objectified relationship IfcRelAssociatesMaterial.

HISTORY New entity in IFC4

Attribute definitions

Attribute	Type	Cardinality	Description	G
AssociatedTo	IfcRelAssociatesMaterial @RelatingMaterial	S[0:?]	Use of the IfcMaterialDefinition subtypes within the material association of an element occurrence or element type. The association is established by the IfcRelAssociatesMaterial relationship. IFC4 CHANGE The inverse attribute has been added.	X
HasExternalReferences	IfcExternalReferenceRelationship @RelatedResourceObjects	S[0:?]	Reference to external references, e.g. library, classification, or document information, that are associated to the material. IFC4 CHANGE The inverse attribute has been added.	X
HasProperties	IfcMaterialProperties @Material	S[0:?]	Material properties assigned to instances of subtypes of IfcMaterialDefinition. IFC4 CHANGE The inverse attribute has been added.	X

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	G
IfcMaterialDefinition
	AssociatedTo	IfcRelAssociatesMaterial @RelatingMaterial	S[0:?]	Use of the IfcMaterialDefinition subtypes within the material association of an element occurrence or element type. The association is established by the IfcRelAssociatesMaterial relationship. IFC4 CHANGE The inverse attribute has been added.	X
	HasExternalReferences	IfcExternalReferenceRelationship @RelatedResourceObjects	S[0:?]	Reference to external references, e.g. library, classification, or document information, that are associated to the material. IFC4 CHANGE The inverse attribute has been added.	X
	HasProperties	IfcMaterialProperties @Material	S[0:?]	Material properties assigned to instances of subtypes of IfcMaterialDefinition. IFC4 CHANGE The inverse attribute has been added.	X

Formal representations

XML Specification

 <xs:element name="IfcMaterialDefinition" type="ifc:IfcMaterialDefinition" abstract="true" substitutionGroup="ifc:Entity" nillable="true"/>

 <xs:complexType name="IfcMaterialDefinition" abstract="true">

  <xs:complexContent>

   <xs:extension base="ifc:Entity">

    <xs:sequence>

     <xs:element name="HasProperties" nillable="true" minOccurs="0">

      <xs:complexType>

       <xs:sequence>

        <xs:element ref="ifc:IfcMaterialProperties" minOccurs="0" maxOccurs="unbounded"/>

       </xs:sequence>

       <xs:attribute ref="ifc:itemType" fixed="ifc:IfcMaterialProperties"/>

       <xs:attribute ref="ifc:cType" fixed="set"/>

       <xs:attribute ref="ifc:arraySize" use="optional"/>

      </xs:complexType>

     </xs:element>

    </xs:sequence>

   </xs:extension>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


ENTITY IfcMaterialDefinition

 ABSTRACT SUPERTYPE OF(ONEOF(IfcMaterial, IfcMaterialConstituent, IfcMaterialConstituentSet, IfcMaterialLayer, IfcMaterialLayerSet, IfcMaterialProfile, IfcMaterialProfileSet));

 INVERSE

  AssociatedTo : SET [0:?] OF IfcRelAssociatesMaterial FOR RelatingMaterial;

  HasExternalReferences : SET [0:?] OF IfcExternalReferenceRelationship FOR RelatedResourceObjects;

  HasProperties : SET [0:?] OF IfcMaterialProperties FOR Material;

END_ENTITY;

 EXPRESS-G diagram

	Materialdefinition
	Material Definition
	Définition de matériau