IFC 4.3.0.0 (IFC4X3) final

7.10.3.24 IfcStructuralSurfaceAction

7.10.3.24.1 Semantic definition

This entity defines an action which is distributed over a surface. A surface action may be connected with a surface member or surface connection.

*Coordinate Systems*:

See definitions at IfcStructuralActivity.

*Topology Use Definitions*:

Standard Case: If connected with a surface item and acting on its entirety, instances of IfcStructuralCurveAction shall not have an ObjectPlacement nor a Representation. It is implied that the placement and representation of the IfcStructuralActivity is the same as the ones of the member or connection.

Special Case 1: If connected with a surface item but acting only on a part of it, instances of IfcStructuralSurfaceAction shall have an ObjectPlacement and Representation, containing an IfcFaceSurface which topologically defines the loaded part of the surface. See IfcStructuralActivity for further definitions.

Special Case 2: If not connected with a structural item (which may happen in an incomplete or conceptual model), a surface action should have an ObjectPlacement and Representation, containing an IfcFaceSurface. See IfcStructuralActivity for further definitions.

Informal Propositions:

  1. If the surface action is of the predefined type CONST, SELF\IfcStructuralActivity.AppliedLoad must not be of type IfcStructuralLoadConfiguration.
  2. If the surface action is of the predefined type BILINEAR, SELF\IfcStructuralActivity.AppliedLoad shall be of type IfcStructuralLoadConfiguration and shall contain three items with two-dimensional IfcStructuralLoadConfiguration.Locations, defining the location of the load samples in local coordinates of the surface action.
  3. If the surface action is of the predefined type DISCRETE, SELF\IfcStructuralActivity.AppliedLoad shall be of type IfcStructuralLoadConfiguration and shall contain two or more items with two-dimensional locations.
  4. Point loads must be of type DISCRETE, thus contain two or more load points. (Single point loads are modeled by IfcStructuralPointLoad.)
  5. All items in SELF\IfcStructuralActivity.AppliedLoad\IfcStructuralLoadConfiguration.Values shall be of the same entity type.

7.10.3.24.2 Entity inheritance

7.10.3.24.3 Attributes

# Attribute Type Description
IfcRoot (4)
1 GlobalId IfcGloballyUniqueId

Assignment of a globally unique identifier within the entire software world.

2 OwnerHistory OPTIONAL IfcOwnerHistory

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,

3 Name OPTIONAL IfcLabel

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.

4 Description OPTIONAL IfcText

Optional description, provided for exchanging informative comments.

IfcObjectDefinition (7)
HasAssignments SET [0:?] OF IfcRelAssigns FOR RelatedObjects

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.

Nests SET [0:1] OF IfcRelNests FOR RelatedObjects

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).

IsNestedBy SET [0:?] OF IfcRelNests FOR RelatingObject

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).

HasContext SET [0:1] OF IfcRelDeclares FOR RelatedDefinitions

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.

IsDecomposedBy SET [0:?] OF IfcRelAggregates FOR RelatingObject

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).

Decomposes SET [0:1] OF IfcRelAggregates FOR RelatedObjects

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).

HasAssociations SET [0:?] OF IfcRelAssociates FOR RelatedObjects

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.

IfcObject (5)
5 ObjectType OPTIONAL IfcLabel

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.

IsDeclaredBy SET [0:1] OF IfcRelDefinesByObject FOR RelatedObjects

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.

Declares SET [0:?] OF IfcRelDefinesByObject FOR RelatingObject

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.

IsTypedBy SET [0:1] OF IfcRelDefinesByType FOR RelatedObjects

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.

IsDefinedBy SET [0:?] OF IfcRelDefinesByProperties FOR RelatedObjects

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.

IfcProduct (5)
6 ObjectPlacement OPTIONAL IfcObjectPlacement

This establishes the object coordinate system and 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 constrained (e.g. relative to grid axes, or to a linear positioning element). The type of placement is determined by the various subtypes of IfcObjectPlacement. An object placement must be provided if a representation is present.

7 Representation OPTIONAL IfcProductRepresentation

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.

ReferencedBy SET [0:?] OF IfcRelAssignsToProduct FOR RelatingProduct

Reference to the IfcRelAssignsToProduct relationship, by which other products, processes, controls, resources or actors (as subtypes of IfcObjectDefinition) can be related to this product.

PositionedRelativeTo SET [0:?] OF IfcRelPositions FOR RelatedProducts

No description available.

ReferencedInStructures SET [0:?] OF IfcRelReferencedInSpatialStructure FOR RelatedElements

No description available.

IfcStructuralActivity (3)
8 AppliedLoad IfcStructuralLoad

Load or result resource object which defines the load type, direction, and load values.

In case of activities which are variably distributed over curves or surfaces, IfcStructuralLoadConfiguration is used which provides a list of load samples and their locations within the load distribution, measured in local coordinates of the curve or surface on which this activity acts. The contents of this load or result distribution may be further restricted by definitions at subtypes of IfcStructuralActivity.

9 GlobalOrLocal IfcGlobalOrLocalEnum

Indicates whether the load directions refer to the global coordinate system (global to the analysis model, i.e. as established by IfcStructuralAnalysisModel.SharedPlacement) or to the local coordinate system (local to the activity or connected item, as established by an explicit or implied representation and its parameter space).

AssignedToStructuralItem SET [0:1] OF IfcRelConnectsStructuralActivity FOR RelatedStructuralActivity

Reference to the IfcRelConnectsStructuralActivity relationship by which activities are connected with structural items.

IfcStructuralAction (1)
10 DestabilizingLoad OPTIONAL IfcBoolean

Indicates if this action may cause a stability problem. If it is 'FALSE', no further investigations regarding stability problems are necessary.

Click to show 25 hidden inherited attributes Click to hide 25 inherited attributes
IfcStructuralSurfaceAction (2)
11 ProjectedOrTrue OPTIONAL IfcProjectedOrTrueLengthEnum

Defines whether load values are given per true lengths of the surface on which they act, or per lengths of the projection of the surface in load direction. The latter is only applicable to loads which act in global coordinate directions.

12 PredefinedType IfcStructuralSurfaceActivityTypeEnum

Type of action according to its distribution of load values.

Table 7.10.3.24.A

7.10.3.24.4 Formal propositions

Name Description
HasObjectType

The attribute ObjectType shall be given if the predefined type is set to USERDEFINED.

(PredefinedType <> IfcStructuralSurfaceActivityTypeEnum.USERDEFINED) OR EXISTS(SELF\IfcObject.ObjectType)
ProjectedIsGlobal

A load can only be related to projected lengths if it was specified in global coordinate directions (i.e. in analysis model coordinate directions). If a load was specified in local coordinate directions, it can only relate to true lengths.

(NOT EXISTS(ProjectedOrTrue)) OR
((ProjectedOrTrue <> PROJECTED_LENGTH) OR
 (SELF\IfcStructuralActivity.GlobalOrLocal = GLOBAL_COORDS))
Table 7.10.3.24.B

7.10.3.24.5 Property sets

  • Pset_Risk
    • RiskName
    • RiskType
    • NatureOfRisk
    • RiskAssessmentMethodology
    • UnmitigatedRiskLikelihood
    • UnmitigatedRiskConsequence
    • UnmitigatedRiskSignificance
    • MitigationPlanned
    • MitigatedRiskLikelihood
    • MitigatedRiskConsequence
    • MitigatedRiskSignificance
    • MitigationProposed
    • AssociatedProduct
    • AssociatedActivity
    • AssociatedLocation
  • Pset_Tolerance
    • ToleranceDescription
    • ToleranceBasis
    • OverallTolerance
    • HorizontalTolerance
    • OrthogonalTolerance
    • VerticalTolerance
    • PlanarFlatness
    • HorizontalFlatness
    • ElevationalFlatness
    • SideFlatness
    • OverallOrthogonality
    • HorizontalOrthogonality
    • OrthogonalOrthogonality
    • VerticalOrthogonality
    • OverallStraightness
    • HorizontalStraightness
    • OrthogonalStraightness
    • VerticalStraightness
  • Pset_Uncertainty
    • UncertaintyBasis
    • UncertaintyDescription
    • HorizontalUncertainty
    • LinearUncertainty
    • OrthogonalUncertainty
    • VerticalUncertainty
  • Qto_BodyGeometryValidation
    • GrossSurfaceArea
    • NetSurfaceArea
    • GrossVolume
    • NetVolume
    • SurfaceGenusBeforeFeatures
    • SurfaceGenusAfterFeatures

7.10.3.24.6 Concept usage

Concept Usage Description
IfcRoot (2)
Revision Control General

Ownership, history, and merge state is captured using IfcOwnerHistory.

Software Identity General

IfcRoot assigns the globally unique ID. In addition it may provide for a name and a description about the concept.

IfcObjectDefinition (9)
Aggregation General

No description available.

Approval Association General

No description available.

Classification Association General

Any object occurrence or object type can have a reference to a specific classification reference, i.e. to a particular facet within a classification system.

Constraint Association General

No description available.

Document Association General

No description available.

Library Association General

No description available.

Material Association General

No description available.

Material Single General

No description available.

Nesting General

No description available.

IfcObject (5)
Assignment to Group General

No description available.

Object Predefined Type General

No description available.

Object Typing General

Any object occurrence can be typed by being assigned to a common object type utilizing this concept. A particular rule, restricting the applicable subtypes of IfcTypeObject that can be assigned, is introduced by overriding this concept at the level of subtypes of IfcObject.

This concept can be applied to the following resources:

Object User Identity General

An attribute Name and optionally Description can be used for all subypes of IfcObject. For those subtypes, that have an object type definition, such as ifcBeam - IfcBeamType, the common Name and optionally Description is associated with the object type.

Property Sets with Override General

Any object occurrence can hold property sets, either directly at the object occurrence as element specific property sets, or at the object type, as type property sets. In this case, the properties that are provided to the object occurrence are the combinations of element specific and type properties. In case, that the same property (within the same property set, is defined both, in occurrence and type properties, the property value of the occurrence property overrides the property value of the type property.

IfcProduct (17)
Body Geometry General

The body or solid model geometric representation of an IfcProduct is typically defined using a Tessellation or Brep. Subtypes may provide recommendations on other representation types that may be used. The following attribute values for the IfcShapeRepresentation holding this geometric representation shall be used:

Box Geometry General

No description available.

CoG Geometry General

No description available.

Mapped Geometry General

No description available.

Product Geometric Representation General

The geometric representation of any IfcProduct is provided by the IfcProductDefinitionShape allowing multiple geometric representations. It uses the Product Placement concept utilizing IfcLocalPlacement to establish an object coordinate system, within all geometric representations are founded.

Product Geometry Colour General

No description available.

Product Geometry Layer General

No description available.

Product Local Placement General

No description available.

Product Relative Positioning General

If the IfcProduct Product Placement is placed relative to an IfcPositioningElement this relationship covers the information on which IfcPositioningElement positions the IfcProduct.

Product Span Positioning General

No description available.

Product Topology Representation General

No description available.

Property Sets for Objects General

This concept can be applied to the following resources:

Quantity Sets General

This concept can be applied to the following resources:

Reference Geometry General

No description available.

Reference SweptSolid Geometry General

No description available.

Reference SweptSolid PolyCurve Geometry General

No description available.

Reference Tessellation Geometry General

No description available.

Click to show 33 hidden inherited concepts Click to hide 33 inherited concepts
Table 7.10.3.24.C

7.10.3.24.7 Formal representation

ENTITY IfcStructuralSurfaceAction
 SUPERTYPE OF (ONEOF
	(IfcStructuralPlanarAction))
 SUBTYPE OF (IfcStructuralAction);
	ProjectedOrTrue : OPTIONAL IfcProjectedOrTrueLengthEnum;
	PredefinedType : IfcStructuralSurfaceActivityTypeEnum;
 WHERE
	HasObjectType : (PredefinedType <> IfcStructuralSurfaceActivityTypeEnum.USERDEFINED) OR EXISTS(SELF\IfcObject.ObjectType);
	ProjectedIsGlobal : (NOT EXISTS(ProjectedOrTrue)) OR
((ProjectedOrTrue <> PROJECTED_LENGTH) OR
 (SELF\IfcStructuralActivity.GlobalOrLocal = GLOBAL_COORDS));
END_ENTITY;

7.10.3.24.8 References

7.10.3.24.9 Changelog

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