IfcRelAssociatesMaterial

Item	SPF	XML	Change	Description
IFC2x3 to IFC4
IfcRelAssociatesMaterial
OwnerHistory			MODIFIED	Instantiation changed to OPTIONAL.
RelatedObjects	X	X	MODIFIED	Type changed from IfcRoot to IfcDefinitionSelect.

Semantic definitions at the entity

Entity definition

IfcRelAssociatesMaterial is an objectified relationship between a material definition and elements or element types to which this material definition applies.

The material definition can be:

assigned to an element occurrence as a specific usage of a layer set or profile set
assigned to an element occurrence or element type as a layer set, profile set, constituent set or a single material

Materials can be arranged by layers and applied to layered elements. Typical elements are walls and slabs.

An IfcMaterialLayerSet, for layered elements with an indication of the layering direction and individual layer thicknesses
An IfcMaterialLayerSetUsage, i.e. a material layer set with positioning information along the reference axis or surface of the element.
NOTE As a material layer set usage is an occurrence based information, that applies to each individual element, it cannot be assigned to an element type.

Material can be applied to profiles. Typical elements using profile material are beam, column, member

An IfcMaterialProfileSet, i.e. a set of material assigned to a set of profiles, with a single material assigned to a single profile as the default.
An IfcMaterialProfileSetUsage, i.e. a material profile set with positioning information relative to the element axis, also refered to as cardinal point.
NOTE As a material profile set usage is an occurrence based information, that applies to each individual element, it cannot be assigned to an element type.

Materials can be arranged by identified parts of a component based element. Typical elements are dorrs/windows (with components such as lining, framing and glazing), or distribution elements.

An IfcMaterialConstituentSet, for component based elements with an indication of the component by keyword to which the material consituent applies.
NOTE See the material use definitions at each applicable subtype of IfcElement or IfcElementType for a provision of these keywords.

As a fallback, or in cases where only a single material information is needed, material information can be directly associated

A single IfcMaterial for any element where the material use definition does not prohibits its direct association
An IfcMaterialList, e.g. for composite elements, without an information, how the different materials are arranged.
DEPRECATED The use of IfcMaterialList is deprecated in IFC4 onwards. Use IfcMaterialConstituentSet instead.

The IfcRelAssociatesMaterial relationship is a special type of the IfcRelAssociates relationship. It can be applied to subtypes of IfcElement and subtypes of IfcElementType.

The IfcElement has an inverse relation to its material definition by the HasAssociations attribute, inherited from IfcObject.
The IfcElementType has an inverse relation to its material definition by the HasAssociations attribute, inherited from IfcPropertyDefinition.

If both, the element occurrence (by an instance of IfcElement) and the element type (by an instance of IfcElementType, connected through IfcRelDefinesByType) have an associated material, then the material associated to the element occurrence overrides the material associated to the element type.

HISTORY New entity in IFC2x.

Informal Propositions:

An IfcMaterialLayerSetUsage shall not be associated with a subtype of IfcElementType, it should only be associated with individual occurrences
An IfcMaterialProfileSetUsage shall not be associated with a subtype of IfcElementType, it should only be associated with individual occurrences

Attribute definitions

#	Attribute	Type	Cardinality	Description	G
6	RelatingMaterial	IfcMaterialSelect		Material definition assigned to the elements or element types.	X

Formal Propositions

Rule	Description
NoVoidElement	The material information must not be associated to a substraction feature (such as an opening) or to a virtual element.
AllowedElements	The material information, using IfcMaterialSelect should be associated to an element occurrence (including structural members) or an element type (including the door and window styles). Also port can have assigned materials, here indicating the fluid flowing from the port.

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	G
IfcRoot
1	GlobalId	IfcGloballyUniqueId		Assignment of a globally unique identifier within the entire software world.	X
2	OwnerHistory	IfcOwnerHistory	?	Assignment of the information about the current ownership of that object, including owning actor, application, local identification and information captured about the recent changes of the object, NOTE only the last modification in stored - either as addition, deletion or modification. IFC4 CHANGE The attribute has been changed to be OPTIONAL.	X
3	Name	IfcLabel	?	Optional name for use by the participating software systems or users. For some subtypes of IfcRoot the insertion of the Name attribute may be required. This would be enforced by a where rule.	X
4	Description	IfcText	?	Optional description, provided for exchanging informative comments.	X
IfcRelationship
IfcRelAssociates
5	RelatedObjects	IfcDefinitionSelect	S[1:?]	Set of object or property definitions to which the external references or information is associated. It includes object and type objects, property set templates, property templates and property sets and contexts. IFC4 CHANGE The attribute datatype has been changed from IfcRoot to IfcDefinitionSelect.	X
IfcRelAssociatesMaterial
6	RelatingMaterial	IfcMaterialSelect		Material definition assigned to the elements or element types.	X

#	Concept	Template	Model View
IfcRoot
	Identity	Software Identity	General Usage
	Revision Control	Revision Control	General Usage

Formal representations

XML Specification

 <xs:element name="IfcRelAssociatesMaterial" type="ifc:IfcRelAssociatesMaterial" substitutionGroup="ifc:IfcRelAssociates" nillable="true"/>

 <xs:complexType name="IfcRelAssociatesMaterial">

  <xs:complexContent>

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

    <xs:sequence>

     <xs:element name="RelatingMaterial">

      <xs:complexType>

       <xs:group ref="ifc:IfcMaterialSelect"/>

      </xs:complexType>

     </xs:element>

    </xs:sequence>

   </xs:extension>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


ENTITY IfcRelAssociatesMaterial

 SUBTYPE OF (IfcRelAssociates);

  RelatingMaterial : IfcMaterialSelect;

 WHERE

  NoVoidElement : SIZEOF(QUERY(temp <* SELF\IfcRelAssociates.RelatedObjects | 

  ('IFCPRODUCTEXTENSION.IfcFeatureElementSubtraction' IN TYPEOF(temp)) OR 

  ('IFCPRODUCTEXTENSION.IfcVirtualElement' IN TYPEOF(temp)) 

)) = 0;
  AllowedElements : SIZEOF(QUERY(temp <* SELF\IfcRelAssociates.RelatedObjects | (

  SIZEOF(TYPEOF(temp) * [   

    'IFCPRODUCTEXTENSION.IfcElement', 

    'IFCPRODUCTEXTENSION.IfcElementType',

    'IFCSHAREDBLDGELEMENTS.IfcWindowStyle',

    'IFCSHAREDBLDGELEMENTS.IfcDoorStyle',

    'IFCSTRUCTURALANALYSISDOMAIN.IfcStructuralMember',

    'IFCPRODUCTEXTENSION.IfcPort']) = 0) 

)) = 0;
END_ENTITY;

 EXPRESS-G diagram

	Ordnet Material zu - Relation
	Rel Associates Material
	Association de matériau

IfcRelAssociatesMaterial

Semantic definitions at the entity

Inherited definitions from supertypes

Definitions applying to General Usage

Formal representations