IfcStructuralSurfaceMember

Definition from buildingSMART International: Instances of the entity IfcStructuralSurfaceMember shall be used to describe planar structural elements.

The material properties are defined by IfcMechanicalMaterialProperties (and subtypes) and they are connected through IfcMaterial and IfcRelAssociatesMaterial and are accessible via the inherited inverse relationship HasAssociations.

HISTORY: New entity in Release IFC2x Edition 2.

Topology Use Definition

Instances of IfcStructuralSurfaceMember shall have a topology representation. It includes a placement and a product representation. The IfcProductRepresentation shall be given by an item of Representations being of type "IfcTopologyRepresentation".

Placement

The placement for IfcStructuralSurfaceMember is determined at its supertype IfcProduct. It is defined by the optional IfcObjectPlacement, referenced by ObjectPlacement at IfcProduct, which establishes, if given, the object coordinate system that is referenced by all topological representations of that product.

If the ObjectPlacement attribute is omitted, then all topological representations are given directly in world coordinates.
If the ObjectPlacement attribute is provided, then it establishes an object coordinate system for all topological representations which are given object coordinates.
- If the PlacementRelTo relationship of IfcLocalPlacement is omitted, the object coordinate system is established within the world coordinate system.
- If the PlacementRelTo relationship of IfcLocalPlacement is given, it shall point to the local placement of the same IfcSpatialStructureElement, which is used in the ContainedInStructure inverse attribute, or to a spatial structure element at a higher level, referenced by that.

Topology Representation

Instances of IfcStructuralSurfaceMember shall have a topology representation given by a face with an optional additional geometric representation of the included surface. It can be provided by either

IfcFace
IfcFaceSurface

which should be the single item of IfcTopologyRepresentation.Items.

EXPRESS specification:

ENTITY IfcStructuralSurfaceMember

SUPERTYPE OF

(IfcStructuralSurfaceMemberVarying)

SUBTYPE OF (

IfcStructuralMember);

PredefinedType

IfcStructuralSurfaceTypeEnum;

Thickness

OPTIONAL IfcPositiveLengthMeasure;

END_ENTITY;

Attribute definitions:

PredefinedType	:	Defines the type of the structural face member.
Thickness	:	Defines the typically understood thickness of the structural face member, i.e. the smallest spatial dimension of the element.

Inheritance graph

ENTITY IfcStructuralSurfaceMember;

ENTITY IfcRoot;

GlobalId

IfcGloballyUniqueId;

OwnerHistory

IfcOwnerHistory;

Name

OPTIONAL IfcLabel;

Description

OPTIONAL IfcText;

ENTITY IfcObjectDefinition;

INVERSE

HasAssignments

SET OF IfcRelAssigns FOR RelatedObjects;

IsDecomposedBy

SET OF IfcRelDecomposes FOR RelatingObject;

Decomposes

SET [0:1] OF IfcRelDecomposes FOR RelatedObjects;

HasAssociations

SET OF IfcRelAssociates FOR RelatedObjects;

ENTITY IfcObject;

ObjectType

OPTIONAL IfcLabel;

INVERSE

IsDefinedBy

SET OF IfcRelDefines FOR RelatedObjects;

ENTITY IfcProduct;

ObjectPlacement

OPTIONAL IfcObjectPlacement;

Representation

OPTIONAL IfcProductRepresentation;

INVERSE

ReferencedBy

SET OF IfcRelAssignsToProduct FOR RelatingProduct;

ENTITY IfcStructuralItem;

INVERSE

AssignedStructuralActivity

SET OF IfcRelConnectsStructuralActivity FOR RelatingElement;

ENTITY IfcStructuralMember;

INVERSE

ReferencesElement

SET OF IfcRelConnectsStructuralElement FOR RelatedStructuralMember;

ConnectedBy

SET OF IfcRelConnectsStructuralMember FOR RelatingStructuralMember;

ENTITY IfcStructuralSurfaceMember;

PredefinedType

IfcStructuralSurfaceTypeEnum;

Thickness

OPTIONAL IfcPositiveLengthMeasure;

END_ENTITY;