IfcStructuralSurfaceMember

Natural language names
Platte / Scheibe
Structural Surface Member
Change log
ItemSPFXMLChangeDescription
IFC2x3 to IFC4
    IfcStructuralSurfaceMember
      OwnerHistoryMODIFIEDInstantiation changed to OPTIONAL.
      PredefinedTypeMODIFIEDType changed from IfcStructuralSurfaceTypeEnum to IfcStructuralSurfaceMemberTypeEnum.
IFC4x2 DRAFT 1
    IfcStructuralSurfaceMember
      PositionedRelativeToADDED
Semantic definitions at the entity
Entity definition

Instances of IfcStructuralSurfaceMember describe face members, that is, structural analysis idealizations of slabs, walls, and shells. Surface members may be planar or curved.

HISTORY  New entity in IFC2x2.
IFC4 CHANGE  Use definitions changed, WHERE rule added.

Coordinate Systems:

See definitions at IfcStructuralItem. The local coordinate system is established by the reference surface given by topology representation.

Material Use Definition

The material of direct instances IfcStructuralSurfaceMember (in contrast to instances of the subtype IfcStructuralSurfaceMemberVarying) is defined by IfcMaterial and attached by the IfcRelAssociatesMaterial.RelatingMaterial. It is accessible by the inverse HasAssociations relationship.

The material is specified minimally by a name which corresponds with an agreed upon standardized structural material designation. An external reference to the source which specifies the material designation should be provided. Alternatively, structural material properties may be provided by means of IfcMechanicalMaterialProperties and IfcExtendedMaterialProperties.

Direct instances of IfcStructuralSurfaceMember are assumed to be located centrically relative to their reference surface. Their depth is provided in the attribute Thickness.

Attribute definitions
#AttributeTypeCardinalityDescription G
8PredefinedTypeIfcStructuralSurfaceMemberTypeEnum Type of member with respect to its load carrying behavior in this analysis idealization.X
9ThicknessIfcPositiveLengthMeasure? Defines the typically understood thickness of the structural surface member, measured normal to its reference surface.X
Formal Propositions
RuleDescription
HasObjectTypeThe attribute ObjectType shall be given if the predefined type is set to USERDEFINED.
Inherited definitions from supertypes
Entity inheritance IfcStructuralSurfaceMemberVarying IfcStructuralMember IfcStructuralItem IfcProduct IfcObject IfcObjectDefinition IfcRoot
Attribute inheritance
#AttributeTypeCardinalityDescriptionG
IfcRoot
1GlobalIdIfcGloballyUniqueId Assignment of a globally unique identifier within the entire software world. X
2OwnerHistoryIfcOwnerHistory? 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
3NameIfcLabel? 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
4DescriptionIfcText? Optional description, provided for exchanging informative comments.X
IfcObjectDefinition
HasAssignmentsIfcRelAssigns
@RelatedObjects
S[0:?]Reference to the relationship objects, that assign (by an association relationship) other subtypes of IfcObject to this object instance. Examples are the association to products, processes, controls, resources or groups.X
NestsIfcRelNests
@RelatedObjects
S[0:1]References to the decomposition relationship being a nesting. It determines that this object definition is a part within an ordered whole/part decomposition relationship. An object occurrence or type can only be part of a single decomposition (to allow hierarchical strutures only).
IFC4 CHANGE  The inverse attribute datatype has been added and separated from Decomposes defined at IfcObjectDefinition.
X
IsNestedByIfcRelNests
@RelatingObject
S[0:?]References to the decomposition relationship being a nesting. It determines that this object definition is the whole within an ordered whole/part decomposition relationship. An object or object type can be nested by several other objects (occurrences or types).
IFC4 CHANGE  The inverse attribute datatype has been added and separated from IsDecomposedBy defined at IfcObjectDefinition.
X
HasContextIfcRelDeclares
@RelatedDefinitions
S[0:1]References to the context providing context information such as project unit or representation context. It should only be asserted for the uppermost non-spatial object.
IFC4 CHANGE  The inverse attribute datatype has been added.
X
IsDecomposedByIfcRelAggregates
@RelatingObject
S[0:?]References to the decomposition relationship being an aggregation. It determines that this object definition is whole within an unordered whole/part decomposition relationship. An object definitions can be aggregated by several other objects (occurrences or parts).
IFC4 CHANGE  The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates.
X
DecomposesIfcRelAggregates
@RelatedObjects
S[0:1]References to the decomposition relationship being an aggregation. It determines that this object definition is a part within an unordered whole/part decomposition relationship. An object definitions can only be part of a single decomposition (to allow hierarchical strutures only).
IFC4 CHANGE  The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates.
X
HasAssociationsIfcRelAssociates
@RelatedObjects
S[0:?]Reference to the relationship objects, that associates external references or other resource definitions to the object.. Examples are the association to library, documentation or classification.X
IfcObject
5ObjectTypeIfcLabel? The type denotes a particular type that indicates the object further. The use has to be established at the level of instantiable subtypes. In particular it holds the user defined type, if the enumeration of the attribute PredefinedType is set to USERDEFINED.
X
IsDeclaredByIfcRelDefinesByObject
@RelatedObjects
S[0:1]Link to the relationship object pointing to the declaring object that provides the object definitions for this object occurrence. The declaring object has to be part of an object type decomposition. The associated IfcObject, or its subtypes, contains the specific information (as part of a type, or style, definition), that is common to all reflected instances of the declaring IfcObject, or its subtypes.
IFC4 CHANGE  New inverse relationship, change made with upward compatibility for file based exchange.
X
DeclaresIfcRelDefinesByObject
@RelatingObject
S[0:?]Link to the relationship object pointing to the reflected object(s) that receives the object definitions. The reflected object has to be part of an object occurrence decomposition. The associated IfcObject, or its subtypes, provides the specific information (as part of a type, or style, definition), that is common to all reflected instances of the declaring IfcObject, or its subtypes.
IFC4 CHANGE  New inverse relationship, change made with upward compatibility for file based exchange.
X
IsTypedByIfcRelDefinesByType
@RelatedObjects
S[0:1]Set of relationships to the object type that provides the type definitions for this object occurrence. The then associated IfcTypeObject, or its subtypes, contains the specific information (or type, or style), that is common to all instances of IfcObject, or its subtypes, referring to the same type.
IFC4 CHANGE  New inverse relationship, the link to IfcRelDefinesByType had previously be included in the inverse relationship IfcRelDefines. Change made with upward compatibility for file based exchange.
X
IsDefinedByIfcRelDefinesByProperties
@RelatedObjects
S[0:?]Set of relationships to property set definitions attached to this object. Those statically or dynamically defined properties contain alphanumeric information content that further defines the object.
IFC4 CHANGE  The data type has been changed from IfcRelDefines to IfcRelDefinesByProperties with upward compatibility for file based exchange.
X
IfcProduct
6ObjectPlacementIfcObjectPlacement? Placement of the product in space, the placement can either be absolute (relative to the world coordinate system), relative (relative to the object placement of another product), or constraint (e.g. relative to grid axes). It is determined by the various subtypes of IfcObjectPlacement, which includes the axis placement information to determine the transformation for the object coordinate system.X
7RepresentationIfcProductRepresentation? Reference to the representations of the product, being either a representation (IfcProductRepresentation) or as a special case a shape representations (IfcProductDefinitionShape). The product definition shape provides for multiple geometric representations of the shape property of the object within the same object coordinate system, defined by the object placement.X
ReferencedByIfcRelAssignsToProduct
@RelatingProduct
S[0:?]Reference to the IfcRelAssignsToProduct relationship, by which other products, processes, controls, resources or actors (as subtypes of IfcObjectDefinition) can be related to this product.X
PositionedRelativeToIfcRelPositions
@RelatedProducts
S[0:1]X
IfcStructuralItem
AssignedStructuralActivityIfcRelConnectsStructuralActivity
@RelatingElement
S[0:?]Inverse relationship to all structural activities (i.e. to actions or reactions) which are assigned to this structural member.X
IfcStructuralMember
ConnectedByIfcRelConnectsStructuralMember
@RelatingStructuralMember
S[0:?]Inverse relationship to all structural connections (i.e. to supports or connecting elements) which are defined for this structural member.X
IfcStructuralSurfaceMember
8PredefinedTypeIfcStructuralSurfaceMemberTypeEnum Type of member with respect to its load carrying behavior in this analysis idealization.X
9ThicknessIfcPositiveLengthMeasure? Defines the typically understood thickness of the structural surface member, measured normal to its reference surface.X
Definitions applying to General Usage

 Instance diagram


Concept usage

Material Layer Set Usage

The Material Layer Set Usage concept applies to this entity.

The material of direct instances IfcStructuralSurfaceMember (in contrast to instances of the subtype IfcStructuralSurfaceMemberVarying) is defined by IfcMaterialLayerSetUsage and attached by the IfcRelAssociatesMaterial.RelatingMaterial. It is accessible by the inverse HasAssociations relationship.

The material is specified minimally by a name which corresponds with an agreed upon standardized structural material designation. An external reference to the source which specifies the material designation should be provided. Alternatively, structural material properties may be provided by means of IfcMaterialProperties.

In the absense of material layer set usage, direct instances of IfcStructuralSurfaceMember are assumed to be located centrically relative to their reference surface. Their depth is provided in the attribute Thickness.



Reference Topology

The Reference Topology concept template applies to this entity as shown in Table 651.

Topology
IfcFaceSurface

Table 651 — IfcStructuralSurfaceMember Reference Topology

Direct instances of IfcStructuralSurfaceMember shall have a topology representation which consists of one IfcFaceSurface, representing the reference surface of the surface member. See definitions at IfcStructuralItem for further specifications.

The local coordinate system is established by the reference surface given by topology representation.



Structural Connectivity

The Structural Connectivity concept template applies to this entity as shown in Table 652.

StructuralConnectionDescription
IfcStructuralCurveConnectionConnections to curve members along edge(s) of surface.
IfcStructuralSurfaceConnectionConnections to surface members within face(s) of surface.

Table 652 — IfcStructuralSurfaceMember Structural Connectivity



mvdXML Specification
<?xml version="1.0"?>
<ConceptRoot xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" uuid="b5b74da7-fec9-4ef9-b5e1-73b7ff050e91" name="IfcStructuralSurfaceMember" status="sample" applicableRootEntity="IfcStructuralSurfaceMember">
  <Applicability uuid="00000000-0000-0000-0000-000000000000" status="sample">
    <Template ref="f62902ac-1ae0-4d2d-86d8-fa2f358484b2" />
    <TemplateRules operator="and" />
  </Applicability>
  <Concepts>
    <Concept uuid="464831c6-2e7f-4a28-a579-f594b7df06a7" name="Material Layer Set Usage" status="sample" override="false">
      <Template ref="6d5fb86f-3f2d-49fb-9528-077855ddcc47" />
    </Concept>
    <Concept uuid="3c54c12b-cd40-4f98-a65f-124b53a0a4f1" name="Reference Topology" status="sample" override="false">
      <Template ref="79dd6317-2390-44ca-88c2-70d46cd5b969" />
      <TemplateRules operator="and">
        <TemplateRule Parameters="Topology[Type]='IfcFaceSurface'" />
      </TemplateRules>
    </Concept>
    <Concept uuid="91437328-4773-43fb-a284-ccf703da116b" name="Structural Connectivity" status="sample" override="false">
      <Template ref="f4f75d4f-6d38-4cbe-9efb-dfb58440dfcb" />
      <TemplateRules operator="and">
        <TemplateRule Description="Connections to curve members along edge(s) of surface." Parameters="StructuralConnection[Type]='IfcStructuralCurveConnection'" />
        <TemplateRule Description="Connections to surface members within face(s) of surface." Parameters="StructuralConnection[Type]='IfcStructuralSurfaceConnection'" />
      </TemplateRules>
    </Concept>
  </Concepts>
</ConceptRoot>
Concept inheritance

#ConceptTemplateModel View
IfcRoot
IdentitySoftware IdentityGeneral Usage
Revision ControlRevision ControlGeneral Usage
IfcObjectDefinition
Classification AssociationClassification AssociationGeneral Usage
IfcObject
Object User IdentityObject User IdentityGeneral Usage
Object Predefined TypeObject Predefined TypeGeneral Usage
Object TypingObject TypingGeneral Usage
Property Sets for ObjectsProperty Sets for ObjectsGeneral Usage
Property Sets with OverrideProperty Sets with OverrideGeneral Usage
IfcProduct
Product PlacementProduct PlacementGeneral Usage
Product Geometric RepresentationProduct Geometric RepresentationGeneral Usage
IfcStructuralSurfaceMember
Material Layer Set UsageMaterial Layer Set UsageGeneral Usage
Reference TopologyReference TopologyGeneral Usage
Structural ConnectivityStructural ConnectivityGeneral Usage
Formal representations
XML Specification
 <xs:element name="IfcStructuralSurfaceMember" type="ifc:IfcStructuralSurfaceMember" substitutionGroup="ifc:IfcStructuralMember" nillable="true"/>
 <xs:complexType name="IfcStructuralSurfaceMember">
  <xs:complexContent>
   <xs:extension base="ifc:IfcStructuralMember">
    <xs:attribute name="PredefinedType" type="ifc:IfcStructuralSurfaceMemberTypeEnum" use="optional"/>
    <xs:attribute name="Thickness" type="ifc:IfcPositiveLengthMeasure" use="optional"/>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>
EXPRESS Specification
ENTITY IfcStructuralSurfaceMember
 SUPERTYPE OF(IfcStructuralSurfaceMemberVarying)
 SUBTYPE OF (IfcStructuralMember);
  PredefinedType : IfcStructuralSurfaceMemberTypeEnum;
  Thickness : OPTIONAL IfcPositiveLengthMeasure;
 WHERE
  HasObjectType : (PredefinedType <> IfcStructuralSurfaceMemberTypeEnum.USERDEFINED) OR EXISTS(SELF\IfcObject.ObjectType);
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

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