IfcStructuralSurfaceMember

Definition from IAI: 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 load carrying behavior of the member, as far as it is taken into account in the analysis.
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;