IfcMaterial

Semantic definitions at the entity

Entity definition

IfcMaterial is a homogeneous or inhomogeneous substance that can be used to form elements (physical products or their components).

IfcMaterial is the basic entity for material designation and definition; this includes identification by name and classification (via reference to an external classification), as well as association of material properties (isotropic or anisotropic) defined by (subtypes of) IfcMaterialProperties. An instance of IfcMaterial may be associated to an element or element type using the IfcRelAssociatesMaterial relationship. The assignment might either be direct as a single material information, or via

a material layer set
a material profile set
a material constituent set

An IfcMaterial may also have presentation information associated. Such presentation information is provided by IfcMaterialDefinitionRepresentation, associating curve styles, hatching definitions or surface colouring/rendering information to a material.

HISTORY New entity in IFC4

IFC4 CHANGE The attributes Description and Category have been added.

Attribute definitions

#	Attribute	Type	Cardinality	Description	C
1	Name	IfcLabel	[1:1]	Name of the material. EXAMPLE A view definition may require Material.Name to uniquely specify e.g. concrete or steel grade, in which case the attribute Material.Category could take the value 'Concrete' or 'Steel'. NOTE Material grade may have different meaning in different view definitions, e.g. strength grade for structural design and analysis, or visible appearance grade in architectural application. Also, more elaborate material grade definition may be associated as classification via inverse attribute HasExternalReferences.	X
2	Description	IfcText	[0:1]	Definition of the material in more descriptive terms than given by attributes Name or Category.	X
3	Category	IfcLabel	[0:1]	Definition of the category (group or type) of material, in more general terms than given by attribute Name. EXAMPLE A view definition may require each Material.Name to be unique, e.g. for each concrete or steel grade used in a project, in which case Material.Category could take the values 'Concrete' or 'Steel'.	X
	HasRepresentation	IfcMaterialDefinitionRepresentation @RepresentedMaterial	S[0:1]	Reference to the IfcMaterialDefinitionRepresentation that provides presentation information to a representation common to this material in style definitions.	X
	IsRelatedWith	IfcMaterialRelationship @RelatedMaterials	S[0:?]	Reference to a material relationship indicating that this material is a part (or constituent) in a material composite.	X
	RelatesTo	IfcMaterialRelationship @RelatingMaterial	S[0:1]	Reference to a material relationship indicating that this material composite has parts (or constituents).	X

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	C
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.	X
	HasExternalReferences	IfcExternalReferenceRelationship @RelatedResourceObjects	S[0:?]	Reference to external references, e.g. library, classification, or document information, that are associated to the material.	X
	HasProperties	IfcMaterialProperties @Material	S[0:?]	Material properties assigned to instances of subtypes of IfcMaterialDefinition.	X
IfcMaterial
1	Name	IfcLabel	[1:1]	Name of the material. EXAMPLE A view definition may require Material.Name to uniquely specify e.g. concrete or steel grade, in which case the attribute Material.Category could take the value 'Concrete' or 'Steel'. NOTE Material grade may have different meaning in different view definitions, e.g. strength grade for structural design and analysis, or visible appearance grade in architectural application. Also, more elaborate material grade definition may be associated as classification via inverse attribute HasExternalReferences.	X
2	Description	IfcText	[0:1]	Definition of the material in more descriptive terms than given by attributes Name or Category.	X
3	Category	IfcLabel	[0:1]	Definition of the category (group or type) of material, in more general terms than given by attribute Name. EXAMPLE A view definition may require each Material.Name to be unique, e.g. for each concrete or steel grade used in a project, in which case Material.Category could take the values 'Concrete' or 'Steel'.	X
	HasRepresentation	IfcMaterialDefinitionRepresentation @RepresentedMaterial	S[0:1]	Reference to the IfcMaterialDefinitionRepresentation that provides presentation information to a representation common to this material in style definitions.	X
	IsRelatedWith	IfcMaterialRelationship @RelatedMaterials	S[0:?]	Reference to a material relationship indicating that this material is a part (or constituent) in a material composite.	X
	RelatesTo	IfcMaterialRelationship @RelatingMaterial	S[0:1]	Reference to a material relationship indicating that this material composite has parts (or constituents).	X

Definitions applying to Common Use Definitions

Instance diagram

Concept usage

Property Sets for Objects

The Property Sets for Objects concept applies to this entity as shown in Table 683.

PredefinedType

Name

Properties

Pset_MaterialCombustion

Single Value

Name	Value
SpecificHeatCapacity	IfcSpecificHeatCapacityMeasure
N20Content	IfcPositiveRatioMeasure
COContent	IfcPositiveRatioMeasure
CO2Content	IfcPositiveRatioMeasure

Pset_MaterialCommon

Single Value

Name	Value
MolecularWeight	IfcMolecularWeightMeasure
Porosity	IfcNormalisedRatioMeasure
MassDensity	IfcMassDensityMeasure

Pset_MaterialEnergy

Single Value

Name	Value
ViscosityTemperatureDerivative	IfcReal
MoistureCapacityThermalGradient	IfcReal
ThermalConductivityTemperatureDerivative	IfcReal
SpecificHeatTemperatureDerivative	IfcReal
VisibleRefractionIndex	IfcReal
SolarRefractionIndex	IfcReal
GasPressure	IfcPressureMeasure

Pset_MaterialFuel

Single Value

Name	Value
CombustionTemperature	IfcThermodynamicTemperatureMeasure
CarbonContent	IfcPositiveRatioMeasure
LowerHeatingValue	IfcHeatingValueMeasure
HigherHeatingValue	IfcHeatingValueMeasure

Pset_MaterialHygroscopic

Single Value

Name	Value
UpperVaporResistanceFactor	IfcPositiveRatioMeasure
LowerVaporResistanceFactor	IfcPositiveRatioMeasure
IsothermalMoistureCapacity	IfcIsothermalMoistureCapacityMeasure
VaporPermeability	IfcVaporPermeabilityMeasure
MoistureDiffusivity	IfcMoistureDiffusivityMeasure

Pset_MaterialMechanical

Single Value

Name	Value
DynamicViscosity	IfcDynamicViscosityMeasure
YoungModulus	IfcModulusOfElasticityMeasure
ShearModulus	IfcModulusOfElasticityMeasure
PoissonRatio	IfcPositiveRatioMeasure
ThermalExpansionCoefficient	IfcThermalExpansionCoefficientMeasure

Pset_MaterialOptical

Single Value

Name	Value
VisibleTransmittance	IfcPositiveRatioMeasure
SolarTransmittance	IfcPositiveRatioMeasure
ThermalIrTransmittance	IfcPositiveRatioMeasure
ThermalIrEmissivityBack	IfcPositiveRatioMeasure
ThermalIrEmissivityFront	IfcPositiveRatioMeasure
VisibleReflectanceBack	IfcPositiveRatioMeasure
VisibleReflectanceFront	IfcPositiveRatioMeasure
SolarReflectanceBack	IfcPositiveRatioMeasure
SolarReflectanceFront	IfcPositiveRatioMeasure

Pset_MaterialThermal

Single Value

Name	Value
SpecificHeatCapacity	IfcSpecificHeatCapacityMeasure
BoilingPoint	IfcThermodynamicTemperatureMeasure
FreezingPoint	IfcThermodynamicTemperatureMeasure
ThermalConductivity	IfcThermalConductivityMeasure

Pset_MaterialWater

Single Value

Name	Value
IsPotable	IfcBoolean
Hardness	IfcIonConcentrationMeasure
AlkalinityConcentration	IfcIonConcentrationMeasure
AcidityConcentration	IfcIonConcentrationMeasure
ImpuritiesContent	IfcNormalisedRatioMeasure
DissolvedSolidsContent	IfcNormalisedRatioMeasure
PHLevel	IfcPHMeasure

Table 683 — IfcMaterial Property Sets for Objects

Concept inheritance

#	Concept	Model View
IfcMaterial
	Property Sets for Objects	Common Use Definitions

Formal representations

XSD Specification

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

 <xs:complexType name="IfcMaterial">

  <xs:complexContent>

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

    <xs:sequence>

     <xs:element name="HasRepresentation" type="ifc:IfcMaterialDefinitionRepresentation" nillable="true" minOccurs="0" maxOccurs="1"/>

    </xs:sequence>

    <xs:attribute name="Name" type="ifc:IfcLabel" use="optional"/>

    <xs:attribute name="Description" type="ifc:IfcText" use="optional"/>

    <xs:attribute name="Category" type="ifc:IfcLabel" use="optional"/>

   </xs:extension>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


ENTITY IfcMaterial

 SUBTYPE OF (IfcMaterialDefinition);

  Name : IfcLabel;

  Description : OPTIONAL IfcText;

  Category : OPTIONAL IfcLabel;

 INVERSE

  HasRepresentation : SET [0:1] OF IfcMaterialDefinitionRepresentation FOR RepresentedMaterial;

  IsRelatedWith : SET OF IfcMaterialRelationship FOR RelatedMaterials;

  RelatesTo : SET [0:1] OF IfcMaterialRelationship FOR RelatingMaterial;

END_ENTITY;

 EXPRESS-G diagram

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Item	SPF	XML	Change	Description
IFC2x3 to IFC4
IfcMaterial
Description			ADDED
Category			ADDED

	Material
	Material
	Matériau