IfcMaterialLayerSet

Natural language names
Gruppe von Materialschichten
Material Layer Set
Ensemble de couches de matériau homogène
Change log
ItemSPFXMLChangeDescription
IFC2x3 to IFC4
    IfcMaterialLayerSet
      DescriptionADDED
Semantic definitions at the entity
Entity definition

The IfcMaterialLayerSet is a designation by which materials of an element constructed of a number of material layers is known and through which the relative positioning of individual layers can be expressed.

The Material Layer Set Base (MlsBase) describes the imaginary axis along which the material layers are positioned.

EXAMPLE A cavity brick wall would be modeled as IfcMaterialLayerSet consisting of three IfcMaterialLayer's: brick, air cavity and brick. The air gap is identified by the IsVentilated flag at IfcMaterialLayer.
HISTORY  New entity in IFC1.0
IFC4 CHANGE  Subtyped from IfcMaterialDefinition, the attribute Description has been added at the end of attribute list.

Attribute use definition

As shown in Figure 385, each IfcMaterialLayerSet implicitly defines a material layer set base line (MlsBase), to which the start of the first IfcMaterialLayer is aligned. The total thickness of a layer set is calculated from the individual layer thicknesses, the first layer starting from the MlsBase and following layers being placed on top of the previous (no gaps or overlaps).

material layer set

Figure 385 — Material layer set

Attribute definitions
#AttributeTypeCardinalityDescription G
1MaterialLayersIfcMaterialLayerL[1:?] Identification of the IfcMaterialLayer’s from which the IfcMaterialLayerSet is composed.X
2LayerSetNameIfcLabel? The name by which the IfcMaterialLayerSet is known. X
3DescriptionIfcText? Definition of the IfcMaterialLayerSet in descriptive terms.
IFC4 CHANGE  The attribute has been added at the end of attribute list.
X
TotalThickness
:=IfcMlsTotalThickness(SELF)
IfcLengthMeasureTotal thickness of the material layer set is derived from the function IfcMlsTotalThickness. X
Inherited definitions from supertypes
Entity inheritance IfcMaterialDefinition
Attribute inheritance
#AttributeTypeCardinalityDescriptionG
IfcMaterialDefinition
AssociatedToIfcRelAssociatesMaterial
@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
HasExternalReferencesIfcExternalReferenceRelationship
@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
HasPropertiesIfcMaterialProperties
@Material
S[0:?]Material properties assigned to instances of subtypes of IfcMaterialDefinition.
IFC4 CHANGE  The inverse attribute has been added.
X
IfcMaterialLayerSet
1MaterialLayersIfcMaterialLayerL[1:?] Identification of the IfcMaterialLayer’s from which the IfcMaterialLayerSet is composed.X
2LayerSetNameIfcLabel? The name by which the IfcMaterialLayerSet is known. X
3DescriptionIfcText? Definition of the IfcMaterialLayerSet in descriptive terms.
IFC4 CHANGE  The attribute has been added at the end of attribute list.
X
TotalThickness
:=IfcMlsTotalThickness(SELF)
IfcLengthMeasureTotal thickness of the material layer set is derived from the function IfcMlsTotalThickness. X
Formal representations
XML Specification
 <xs:element name="IfcMaterialLayerSet" type="ifc:IfcMaterialLayerSet" substitutionGroup="ifc:IfcMaterialDefinition" nillable="true"/>
 <xs:complexType name="IfcMaterialLayerSet">
  <xs:complexContent>
   <xs:extension base="ifc:IfcMaterialDefinition">
    <xs:sequence>
     <xs:element name="MaterialLayers">
      <xs:complexType>
       <xs:sequence>
        <xs:element ref="ifc:IfcMaterialLayer" maxOccurs="unbounded"/>
       </xs:sequence>
       <xs:attribute ref="ifc:itemType" fixed="ifc:IfcMaterialLayer"/>
       <xs:attribute ref="ifc:cType" fixed="list"/>
       <xs:attribute ref="ifc:arraySize" use="optional"/>
      </xs:complexType>
     </xs:element>
    </xs:sequence>
    <xs:attribute name="LayerSetName" type="ifc:IfcLabel" use="optional"/>
    <xs:attribute name="Description" type="ifc:IfcText" use="optional"/>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>
EXPRESS Specification
ENTITY IfcMaterialLayerSet
 SUBTYPE OF (IfcMaterialDefinition);
  MaterialLayers : LIST [1:?] OF IfcMaterialLayer;
  LayerSetName : OPTIONAL IfcLabel;
  Description : OPTIONAL IfcText;
 DERIVE
  TotalThickness : IfcLengthMeasure := IfcMlsTotalThickness(SELF);
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

References  References: IfcMaterialLayer IfcMaterialLayerSetUsage

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