 | gleichm盲脽ige / ver盲nderliche Fl盲chenlast |
 | Structural Surface Action |
| Item | SPF | XML | Change | Description | IFC2x3 to IFC4 |
|---|---|---|---|---|
| IfcStructuralSurfaceAction | ADDED | IFC4 Addendum 1 | ||
| IfcStructuralSurfaceAction | ||||
| DestabilizingLoad | MODIFIED | Type changed from BOOLEAN to IfcBoolean. |
This entity defines an action which is distributed over a surface. A surface action may be connected with a surface member or surface connection.
HISTORY New entity in IFC4.
IFC4 CHANGE Former entity IfcStructuralPlanarActionVarying from IFC2x2 has been removed and are replaced by this entity.
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:
| # | Attribute | Type | Cardinality | Description | G |
|---|---|---|---|---|---|
| 11 | ProjectedOrTrue | 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. | X |
| 12 | PredefinedType | IfcStructuralSurfaceActivityTypeEnum | Type of action according to its distribution of load values. | X |
| Rule | Description |
|---|---|
| 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. |
| HasObjectType | The attribute ObjectType shall be given if the predefined type is set to USERDEFINED. |
| # | Attribute | Type | Cardinality | Description | G |
|---|---|---|---|---|---|
| IfcRoot | |||||
| 1 | GlobalId | IfcGloballyUniqueId | Assignment of a globally unique identifier within the entire software world. | X | |
| 2 | OwnerHistory | 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,
NOTE only the last modification in stored - either as addition, deletion or modification. IFC4 CHANGE The attribute has been changed to be OPTIONAL. | X |
| 3 | Name | 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. | X |
| 4 | Description | IfcText | ? | Optional description, provided for exchanging informative comments. | X |
| IfcObjectDefinition | |||||
| HasAssignments | IfcRelAssigns @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 | |
| Nests | IfcRelNests @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 | |
| IsNestedBy | IfcRelNests @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 | |
| HasContext | IfcRelDeclares @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 | |
| IsDecomposedBy | IfcRelAggregates @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 | |
| Decomposes | IfcRelAggregates @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 | |
| HasAssociations | IfcRelAssociates @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 | |||||
| 5 | ObjectType | 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.
| X |
| IsDeclaredBy | IfcRelDefinesByObject @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 | |
| Declares | IfcRelDefinesByObject @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 | |
| IsTypedBy | IfcRelDefinesByType @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 | |
| IsDefinedBy | IfcRelDefinesByProperties @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 | |||||
| 6 | ObjectPlacement | IfcObjectPlacement | ? | 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 |
| 7 | Representation | 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. | X |
| ReferencedBy | IfcRelAssignsToProduct @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 | |
| IfcStructuralActivity | |||||
| 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. | X | |
| 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).
NOTE, the informal definition of IfcRepresentationResource.IfcGlobalOrLocalEnum doe s not distinguish between "global coordinate system" and "world coordinate system". On the other hand, this distinction is necessary in the IfcStructuralAnalysisDomain where the shared "global" coordinate system of an analysis model may very well not be the same as the project-wide world coordinate system. NOTE In the scope of IfcStructuralActivity.GlobalOrLocal, the meaning of GLOBAL_COORDS is therefore not to be taken as world coordinate system but as the analysis model specific shared coordinate system. In contrast, LOCAL_COORDS is to be taken as coordinates which are local to individual structural items and activities, as established by subclass-specific geometry use definitions. | X | |
| AssignedToStructuralItem | IfcRelConnectsStructuralActivity @RelatedStructuralActivity | S[0:1] | Reference to the IfcRelConnectsStructuralActivity relationship by which activities are connected with structural items. | X | |
| IfcStructuralAction | |||||
| 10 | DestabilizingLoad | IfcBoolean | ? | Indicates if this action may cause a stability problem. If it is 'FALSE', no further investigations regarding stability problems are necessary. | X |
| IfcStructuralSurfaceAction | |||||
| 11 | ProjectedOrTrue | 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. | X |
| 12 | PredefinedType | IfcStructuralSurfaceActivityTypeEnum | Type of action according to its distribution of load values. | X | |
Structural Activity
The Structural Activity concept template applies to this entity as shown in Table 635.
| ||||||
Table 635 — IfcStructuralSurfaceAction Structural Activity |
Instance diagram
<?xml version="1.0"?>
<ConceptRoot xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" uuid="a6510f06-e9d8-4332-89ff-d140ae87eeb7" name="IfcStructuralSurfaceAction" status="sample" applicableRootEntity="IfcStructuralSurfaceAction">
<Applicability uuid="00000000-0000-0000-0000-000000000000" status="sample">
<Template ref="9e1e3eaf-dd6e-4db3-a3a0-e926399538de" />
<TemplateRules operator="and" />
</Applicability>
<Concepts>
<Concept uuid="c855400b-6927-474f-90c3-5f09d6dc6191" name="Structural Activity" status="sample" override="false">
<Template ref="9390ca72-d8e2-482b-9986-e0e1d15e7194" />
<TemplateRules operator="and">
<TemplateRule Description="Force and moment within a surface member." Parameters="AppliedLoad[Type]='IfcStructuralLoadPlanarForce' AND RelatingElement[Value]='IfcStructuralSurfaceMember'" />
</TemplateRules>
</Concept>
</Concepts>
</ConceptRoot>
| # | Concept | Template | Model View |
|---|---|---|---|
| IfcRoot | |||
| Identity | Software Identity | General Usage | |
| Revision Control | Revision Control | General Usage | |
| IfcObjectDefinition | |||
| Classification Association | Classification Association | General Usage | |
| IfcObject | |||
| Object User Identity | Object User Identity | General Usage | |
| Object Predefined Type | Object Predefined Type | General Usage | |
| Object Typing | Object Typing | General Usage | |
| Property Sets for Objects | Property Sets for Objects | General Usage | |
| Property Sets with Override | Property Sets with Override | General Usage | |
| IfcProduct | |||
| Product Placement | Product Placement | General Usage | |
| Product Geometric Representation | Product Geometric Representation | General Usage | |
| IfcStructuralSurfaceAction | |||
| Structural Activity | Structural Activity | General Usage | |
<xs:element name="IfcStructuralSurfaceAction" type="ifc:IfcStructuralSurfaceAction" substitutionGroup="ifc:IfcStructuralAction" nillable="true"/>
<xs:complexType name="IfcStructuralSurfaceAction">
<xs:complexContent>
<xs:extension base="ifc:IfcStructuralAction">
<xs:attribute name="ProjectedOrTrue" type="ifc:IfcProjectedOrTrueLengthEnum" use="optional"/>
<xs:attribute name="PredefinedType" type="ifc:IfcStructuralSurfaceActivityTypeEnum" use="optional"/>
</xs:extension>
</xs:complexContent>
</xs:complexType>
ENTITY IfcStructuralSurfaceAction
SUPERTYPE OF(IfcStructuralPlanarAction)
SUBTYPE OF (IfcStructuralAction);
ProjectedOrTrue : OPTIONAL IfcProjectedOrTrueLengthEnum;
PredefinedType : IfcStructuralSurfaceActivityTypeEnum;
WHERE
ProjectedIsGlobal : (NOT EXISTS(ProjectedOrTrue)) OR
((ProjectedOrTrue <> PROJECTED_LENGTH) OR
(SELF\IfcStructuralActivity.GlobalOrLocal = GLOBAL_COORDS));
HasObjectType : (PredefinedType <> IfcStructuralSurfaceActivityTypeEnum.USERDEFINED) OR EXISTS(SELF\IfcObject.ObjectType);
END_ENTITY;
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