IfcTendon

BACnet MVD

#### IfcTendon

Natural language names

| Spannglied
| Tendon
| Cable

Change log

Item | SPF | XML | Change | Description
--- | --- | --- | --- | ---
IFC2x3 to IFC4
IfcTendon |  |  |  |
OwnerHistory |  |  | MODIFIED | Instantiation changed to OPTIONAL.
PredefinedType |  |  | MODIFIED | Instantiation changed to OPTIONAL.
NominalDiameter |  |  | MODIFIED | Instantiation changed to OPTIONAL.
CrossSectionArea |  |  | MODIFIED | Instantiation changed to OPTIONAL.
IFC4 Addendum 1
IfcTendon |  |  |  |
HasCoverings |  |  | ADDED |

##### Semantic definitions at the entity

Entity definition

A tendon is a steel element such as a wire, cable, bar, rod, or strand used to impart prestress to concrete when the element is tensioned.

> NOTE Definition according to ISO 6707-1: steel bar(s) or groups of bars, strands or wires given a tensile stress that produces a compressive stress in prestressed concrete or masonry.

> HISTORY New entity in IFC2x2.

> IFC4 CHANGE Attribute PredefinedType made optional. NominalDiameter and CrossSectionArea made optional and deprecated; this information can now be provided by IfcTendonType. Description of FrictionCoefficient corrected.

Attribute definitions

# | Attribute | Type | Cardinality | Description | B
--- | --- | --- | --- | --- | ---

10

PredefinedType

IfcTendonTypeEnum

?

Predefined generic types for a tendon.

> IFC4 CHANGE Attribute made optional.

X

11

NominalDiameter

IfcPositiveLengthMeasure

?

The nominal diameter defining the cross-section size of the tendon.

> IFC4 CHANGE Attribute made optional and deprecated. Use respective attribute at IfcTendonType instead.

X

12

CrossSectionArea

IfcAreaMeasure

?

The effective cross-section area of the tendon.

> IFC4 CHANGE Attribute made optional and deprecated. Use respective attribute at IfcTendonType instead.

X

13 | TensionForce | IfcForceMeasure | ? | The maximum allowed tension force that can be applied on the tendon. |  | X
14 | PreStress | IfcPressureMeasure | ? | The prestress to be applied on the tendon. |  | X
15 | FrictionCoefficient | IfcNormalisedRatioMeasure | ? | The friction coefficient between tendon and tendon sheet while the tendon is unbonded. |  | X
16 | AnchorageSlip | IfcPositiveLengthMeasure | ? | The deformation of an anchor or slippage of tendons when the prestressing device is released. |  | X
17 | MinCurvatureRadius | IfcPositiveLengthMeasure | ? | The smallest curvature radius calculated on the whole effective length of the tendon where the tension properties are still valid. |  | X

Formal Propositions

Rule | Description
--- | ---
CorrectPredefinedType | Either the PredefinedType attribute is unset (e.g. because an IfcTendonType is associated), or the inherited attribute ObjectType shall be provided, if the PredefinedType is set to USERDEFINED.
CorrectTypeAssigned | If this occurrence is defined by a type object, the latter has to be an IfcTendonType.

##### Inherited definitions from supertypes

Entity inheritance
Attribute inheritance

# | Attribute | Type | Cardinality | Description | B
--- | --- | --- | --- | --- | ---
IfcRoot
1 | GlobalId | IfcGloballyUniqueId |  | Assignment of a globally unique identifier within the entire software world. | X | 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

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 | 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

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

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

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 | 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

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 | 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 | 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
IfcElement
8 | Tag | IfcIdentifier | ? | The tag (or label) identifier at the particular instance of a product, e.g. the serial number, or the position number. It is the identifier at the occurrence level. |  | X
| FillsVoids | IfcRelFillsElement @RelatedBuildingElement | S[0:1] | Reference to the IfcRelFillsElement Relationship that puts the element as a filling into the opening created within another element. |  | X
| ConnectedTo | IfcRelConnectsElements @RelatingElement | S[0:?] | Reference to the element connection relationship. The relationship then refers to the other element to which this element is connected to. | X | X

IsInterferedByElements

IfcRelInterferesElements
@RelatedElement

S[0:?]

Reference to the interference relationship to indicate the element that is interfered. The relationship, if provided, indicates that this element has an interference with one or many other elements.

> NOTE There is no indication of precedence between IsInterferedByElements and InterferesElements.

> IFC4 CHANGE New inverse relationship.

X

X

InterferesElements

IfcRelInterferesElements
@RelatingElement

S[0:?]

Reference to the interference relationship to indicate the element that interferes. The relationship, if provided, indicates that this element has an interference with one or many other elements.

> NOTE There is no indication of precedence between IsInterferedByElements and InterferesElements.

> IFC4 CHANGE New inverse relationship.

X

| HasProjections | IfcRelProjectsElement @RelatingElement | S[0:?] | Projection relationship that adds a feature (using a Boolean union) to the IfcBuildingElement. | X | X

ReferencedInStructures

IfcRelReferencedInSpatialStructure
@RelatedElements

S[0:?]

Reference relationship to the spatial structure element, to which the element is additionally associated. This relationship may not be hierarchical, an element may be referenced by zero, one or many spatial structure elements.

> IFC2x3 CHANGE The inverse attribute has been added with upward compatibility for file based exchange.

X

| HasOpenings | IfcRelVoidsElement @RelatingBuildingElement | S[0:?] | Reference to the IfcRelVoidsElement relationship that creates an opening in an element. An element can incorporate zero-to-many openings. For each opening, that voids the element, a new relationship IfcRelVoidsElement is generated. |  | X
| IsConnectionRealization | IfcRelConnectsWithRealizingElements @RealizingElements | S[0:?] | Reference to the connection relationship with realizing element. The relationship, if provided, assigns this element as the realizing element to the connection, which provides the physical manifestation of the connection relationship. |  | X
| ProvidesBoundaries | IfcRelSpaceBoundary @RelatedBuildingElement | S[0:?] | Reference to space boundaries by virtue of the objectified relationship IfcRelSpaceBoundary. It defines the concept of an element bounding spaces. |  | X
| ConnectedFrom | IfcRelConnectsElements @RelatedElement | S[0:?] | Reference to the element connection relationship. The relationship then refers to the other element that is connected to this element. | X | X
| ContainedInStructure | IfcRelContainedInSpatialStructure @RelatedElements | S[0:1] | Containment relationship to the spatial structure element, to which the element is primarily associated. This containment relationship has to be hierachical, i.e. an element may only be assigned directly to zero or one spatial structure. |  | X
| HasCoverings | IfcRelCoversBldgElements @RelatingBuildingElement | S[0:?] | Reference to IfcCovering by virtue of the objectified relationship IfcRelCoversBldgElement. It defines the concept of an element having coverings associated. |  | X
IfcElementComponent
IfcReinforcingElement

9

SteelGrade

IfcLabel

?

Deprecated.

> IFC4 CHANGE Attribute deprecated. Use material association at IfcReinforcingElementType instead.

X

IfcTendon

10

PredefinedType

IfcTendonTypeEnum

?

Predefined generic types for a tendon.

> IFC4 CHANGE Attribute made optional.

X

11

NominalDiameter

IfcPositiveLengthMeasure

?

The nominal diameter defining the cross-section size of the tendon.

> IFC4 CHANGE Attribute made optional and deprecated. Use respective attribute at IfcTendonType instead.

X

12

CrossSectionArea

IfcAreaMeasure

?

The effective cross-section area of the tendon.

> IFC4 CHANGE Attribute made optional and deprecated. Use respective attribute at IfcTendonType instead.

X

13 | TensionForce | IfcForceMeasure | ? | The maximum allowed tension force that can be applied on the tendon. |  | X
14 | PreStress | IfcPressureMeasure | ? | The prestress to be applied on the tendon. |  | X
15 | FrictionCoefficient | IfcNormalisedRatioMeasure | ? | The friction coefficient between tendon and tendon sheet while the tendon is unbonded. |  | X
16 | AnchorageSlip | IfcPositiveLengthMeasure | ? | The deformation of an anchor or slippage of tendons when the prestressing device is released. |  | X
17 | MinCurvatureRadius | IfcPositiveLengthMeasure | ? | The smallest curvature radius calculated on the whole effective length of the tendon where the tension properties are still valid. |  | X

##### Definitions applying to Design Transfer View

Concept inheritance

# | Concept | Template | Model View
--- | --- | --- | ---
IfcRoot
| Revision Control | Revision Control | Design Transfer View
IfcElement
| Product Grid Placement | Product Grid Placement | Design Transfer View
| Body SurfaceModel Geometry | Body SurfaceModel Geometry | Design Transfer View
| Body CSG Geometry | Body CSG Geometry | Design Transfer View
| Body Clipping Geometry | Body Clipping Geometry | Design Transfer View
| Body Brep Geometry | Body Brep Geometry | Design Transfer View
| Body AdvancedBrep Geometry | Body AdvancedBrep Geometry | Design Transfer View
| Element Projecting | Element Projecting | Design Transfer View
| Element Interference | Element Interference | Design Transfer View

##### Definitions applying to BACnet View

Concept inheritance

# | Concept | Template | Model View
--- | --- | --- | ---
IfcRoot
| Revision Control | Revision Control | Design Transfer View
IfcElement
| Product Grid Placement | Product Grid Placement | Design Transfer View
| Body SurfaceModel Geometry | Body SurfaceModel Geometry | Design Transfer View
| Body CSG Geometry | Body CSG Geometry | Design Transfer View
| Body Clipping Geometry | Body Clipping Geometry | Design Transfer View
| Body Brep Geometry | Body Brep Geometry | Design Transfer View
| Body AdvancedBrep Geometry | Body AdvancedBrep Geometry | Design Transfer View
| Element Projecting | Element Projecting | Design Transfer View
| Element Interference | Element Interference | Design Transfer View

##### Formal representations

XML Specification
`<xs:element name="IfcTendon" type="ifc:IfcTendon" substitutionGroup="ifc:IfcReinforcingElement" nillable="true"/>
<xs:complexType name="IfcTendon">
<xs:complexContent>
<xs:extension base="ifc:IfcReinforcingElement">
<xs:attribute name="PredefinedType" type="ifc:IfcTendonTypeEnum" use="optional"/>
<xs:attribute name="NominalDiameter" type="ifc:IfcPositiveLengthMeasure" use="optional"/>
<xs:attribute name="CrossSectionArea" type="ifc:IfcAreaMeasure" use="optional"/>
<xs:attribute name="TensionForce" type="ifc:IfcForceMeasure" use="optional"/>
<xs:attribute name="PreStress" type="ifc:IfcPressureMeasure" use="optional"/>
<xs:attribute name="FrictionCoefficient" type="ifc:IfcNormalisedRatioMeasure" use="optional"/>
<xs:attribute name="AnchorageSlip" type="ifc:IfcPositiveLengthMeasure" use="optional"/>
<xs:attribute name="MinCurvatureRadius" type="ifc:IfcPositiveLengthMeasure" use="optional"/>
</xs:extension>
</xs:complexContent>
</xs:complexType>
`
EXPRESS Specification
`ENTITY IfcTendon
SUBTYPE OF (IfcReinforcingElement);
PredefinedType : OPTIONAL IfcTendonTypeEnum;
NominalDiameter : OPTIONAL IfcPositiveLengthMeasure;
CrossSectionArea : OPTIONAL IfcAreaMeasure;
TensionForce : OPTIONAL IfcForceMeasure;
PreStress : OPTIONAL IfcPressureMeasure;
FrictionCoefficient : OPTIONAL IfcNormalisedRatioMeasure;
AnchorageSlip : OPTIONAL IfcPositiveLengthMeasure;
MinCurvatureRadius : OPTIONAL IfcPositiveLengthMeasure;
WHERE
CorrectPredefinedType : NOT(EXISTS(PredefinedType)) OR
(PredefinedType <> IfcTendonTypeEnum.USERDEFINED) OR
((PredefinedType = IfcTendonTypeEnum.USERDEFINED) AND EXISTS (SELF\IfcObject.ObjectType));
CorrectTypeAssigned : (SIZEOF(IsTypedBy) = 0) OR
('IFCSTRUCTURALELEMENTSDOMAIN.IfcTendonType' IN TYPEOF(SELF\IfcObject.IsTypedBy[1].RelatingType))
;
END_ENTITY;

EXPRESS-G diagram

`

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