IFC 4.3.x development

5.4.3.37 IfcRelAssociatesMaterial

Change log

IFC4

additionswhere_rulesAllowedElements
additionswhere_rulesNoVoidElement
deletionswhere_rulesWR21
deletionswhere_rulesWR22

IFC4X1

additionswhere_rulesAllowedElements
additionswhere_rulesNoVoidElement
deletionswhere_rulesAllowedElements
deletionswhere_rulesNoVoidElement

IFC4X2

additionswhere_rulesAllowedElements
additionswhere_rulesNoVoidElement
deletionswhere_rulesAllowedElements
deletionswhere_rulesNoVoidElement

IFC4X3_RC3

additionswhere_rulesAllowedElements
additionswhere_rulesNoVoidElement
deletionswhere_rulesAllowedElements
deletionswhere_rulesNoVoidElement

5.4.3.37.1 Semantic definitions at the entity

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.

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:

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

5.4.3.37.1 Attributes

#Attribute Type Description
IfcRoot
1GlobalId IfcGloballyUniqueId Assignment of a globally unique identifier within the entire software world.
2OwnerHistory OPTIONAL 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.
3Name OPTIONAL 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.
4Description OPTIONAL IfcText Optional description, provided for exchanging informative comments.
IfcRelationship
IfcRelAssociates
5RelatedObjects SET [1:?] OF IfcDefinitionSelectSet 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.
IfcRelAssociatesMaterial
6RelatingMaterialIfcMaterialSelect Material definition assigned to the elements or element types.

5.4.3.37.2 Entity inheritance

dot_inheritance IfcRelAssociatesMaterial IfcRelAssociatesMaterial IfcRelAssociates IfcRelAssociates IfcRelAssociatesMaterial->IfcRelAssociates IfcRelAssociates_children 6 more... IfcRelAssociates_children->IfcRelAssociates IfcRelationship IfcRelationship IfcRelAssociates->IfcRelationship IfcRelationship_children 5 more... IfcRelationship_children->IfcRelationship IfcRoot IfcRoot IfcRelationship->IfcRoot IfcObjectDefinition IfcObjectDefinition IfcObjectDefinition->IfcRoot IfcPropertyDefinition IfcPropertyDefinition IfcPropertyDefinition->IfcRoot

5.4.3.37.3 Definitions applying to General Usage

5.4.3.37.3.1 Identity

IfcRoot assigns the globally unique ID. In addition it may provide for a name and a description about the concept.

5.4.3.37.3.2 Revision Control

Ownership, history, and merge state is captured using IfcOwnerHistory.

5.4.3.37.4 Formal representations

ENTITY IfcRelAssociatesMaterial
 SUBTYPE OF (IfcRelAssociates);
	RelatingMaterial : IfcMaterialSelect;
 WHERE
	NoVoidElement : SIZEOF(QUERY(temp <* SELF\IfcRelAssociates.RelatedObjects | 
  ('IFC4X3_DEV.IFCFEATUREELEMENTSUBTRACTION' IN TYPEOF(temp)) OR 
  ('IFC4X3_DEV.IFCVIRTUALELEMENT' IN TYPEOF(temp)) 
)) = 0;
	AllowedElements : SIZEOF(QUERY(temp <* SELF\IfcRelAssociates.RelatedObjects | (
  SIZEOF(TYPEOF(temp) * [   
    'IFC4X3_DEV.IFCELEMENT', 
    'IFC4X3_DEV.IFCELEMENTTYPE',
    'IFC4X3_DEV.IFCWINDOWSTYLE',
    'IFC4X3_DEV.IFCDOORSTYLE',
    'IFC4X3_DEV.IFCSTRUCTURALMEMBER',
    'IFC4X3_DEV.IFCPORT']) = 0) 
)) = 0;
END_ENTITY;