IfcStructuralAnalysisModel

Semantic definitions at the entity

Entity definition

The IfcStructuralAnalysisModel is used to assemble all information needed to represent a structural analysis model. It encompasses certain general properties (such as analysis type), references to all contained structural members, structural supports or connections, as well as loads and the respective load results.

Important functionalities for the description of an analysis model are derived from existing IFC entities:

From IfcSystem it inherits the ability to couple the built system via IfcRelReferencedInSpatialStructure to one or more IfcSpatialElement subtypes as necessary.
From IfcGroup it inherits the inverse attribute IsGroupedBy, pointing to the relationship class IfcRelAssignsToGroup . This allows the grouping of structural members (instances of IfcStructuralMember), and supports (instances of IfcStructuralConnection which belong to a specific analysis model.

NOTE Loads (as instances of IfcStructuralAction are not included through IsGroupedBy. Loads are assigned through the LoadedBy attribute relationship, using load groups as a grouping mechanism. Only top-level load groups should be referenced via LoadedBy, i.e. load combinations if any load combinations exist, or load cases if no load combinations exist in this analysis model.

NOTE Results (as instances of IfcStructuralReaction are not included through IsGroupedBy. Results are assigned through the HasResults attribute relationship, using result groups as a grouping mechanism.

From IfcObjectDefinition it inherits the inverse attribute IsDecomposedBy pointing to the relationship class IfcRelAggregates. It provides the hierarchy between the separate (partial) analysis models.

HISTORY New entity in IFC2x2.

IFC4 CHANGE Attribute SharedPlacement and informal propositions added, allowing for easy retrieval of the common object placement and for specification of the analysis model's coordiante system before any structural item is instantiated. WHERE rule added.

Informal Propositions:

If one or more structural item (instance of a subtype of IfcStructuralItem is grouped into an IfcStructuralAnalysisModel, the attribute SharedPlacement shall be provided with a value.
The ObjectPlacement of all structural items which are grouped into the same instance of IfcStructuralAnalysisModel shall refer to the same instance of IfcObjectPlacement as IfcStructuralAnalysisModel.SharedPlacement.

NOTE This rule is necessary to achieve consistent topology representations. The topology representations of structural items in an analysis model are meant to share vertices and edges und must therefore have the same object placement.

NOTE A structural item may be grouped into more than one analysis model. In this case, all these models must use the same instance of IfcObjectPlacement.

Attribute definitions

#	Attribute	Type	Cardinality	Description	G
6	PredefinedType	IfcAnalysisModelTypeEnum		A list of types to further identify the object. Some property sets may be specifically applicable to one of these types. NOTE If the object has an associated IfcTypeObject with a PredefinedType, then this attribute shall not be used.	X
7	OrientationOf2DPlane	IfcAxis2Placement3D	?		X
8	LoadedBy	IfcStructuralLoadGroup	? S[1:?]		X
9	HasResults	IfcStructuralResultGroup	? S[1:?]		X
10	SharedPlacement	IfcObjectPlacement	?		X

Formal Propositions

Rule	Description
CorrectPredefinedType	Either the PredefinedType attribute is unset, or the inherited attribute ObjectType shall be provided, if the PredefinedType is set to USERDEFINED.

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	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
IfcGroup
	IsGroupedBy	IfcRelAssignsToGroup @RelatingGroup	S[0:?]	Reference to the relationship IfcRelAssignsToGroup that assigns the one to many group members to the IfcGroup object. IFC4 CHANGE The cardinality has been changed from 1..1 to 0..? in order to allow the exchange of a group concept without having already group members assigned. It now also allows the use of many instances of IfcRelAssignsToGroup to assign the group members. The change has been done with upward compatibility for file based exchange.	X
	ReferencedInStructures	IfcRelReferencedInSpatialStructure @RelatedElements	S[0:?]	Reference to the relationship IfcRelReferencedInSpatialStructure that relates the group to a spatial element.	X
IfcSystem
	ServicesBuildings	IfcRelServicesBuildings @RelatingSystem	S[0:1]	Reference to the ~~building~~ spatial structure via the objectified relationship IfcRelServicesBuildings, which is serviced by the system.	X
	ServicesFacilities	IfcRelReferencedInSpatialStructure @RelatedElements	S[0:?]		X
IfcStructuralAnalysisModel
6	PredefinedType	IfcAnalysisModelTypeEnum		A list of types to further identify the object. Some property sets may be specifically applicable to one of these types. NOTE If the object has an associated IfcTypeObject with a PredefinedType, then this attribute shall not be used.	X
7	OrientationOf2DPlane	IfcAxis2Placement3D	?		X
8	LoadedBy	IfcStructuralLoadGroup	? S[1:?]		X
9	HasResults	IfcStructuralResultGroup	? S[1:?]		X
10	SharedPlacement	IfcObjectPlacement	?		X

Definitions applying to General Usage

Instance diagram

IfcStructuralAnalysisModel

Concept usage

Aggregation

The Aggregation concept template applies to this entity as shown in Table 702.

Table 702 — IfcStructuralAnalysisModel Aggregation

Group Assignment

The Group Assignment concept template applies to this entity as shown in Table 703.

IsGrouped	RelatedObjects	Description
		Structural members and connections assigned to the analysis model.

Table 703 — IfcStructuralAnalysisModel Group Assignment

mvdXML Specification


<?xml version="1.0" encoding="utf-8"?>

<ConceptRoot xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" uuid="79e6d5d3-2c4d-471d-9bf7-9f5a42693def" name="IfcStructuralAnalysisModel" applicableRootEntity="IfcStructuralAnalysisModel">

 <Applicability>

  <Template ref="a9794eea-52aa-4c72-a678-750b0dbdc8fd" />

  <TemplateRules operator="and">

  </TemplateRules>

 </Applicability>

 <Concepts>

  <Concept uuid="076fe87b-714b-4022-a493-a3b256383896" name="Aggregation">

   <Template ref="02eefcc6-b26c-4f20-9c7c-c30ae74eb9a9" />

   <TemplateRules operator="and">

    <TemplateRule Description="This relationship provides the hierarchy between separate (partial) analysis models." />

   </TemplateRules>

  </Concept>

  <Concept uuid="3c6c3bab-1626-47cc-9e86-e36b0d86dc7e" name="Group Assignment">

   <Template ref="f567967f-5493-44d9-ac51-937c09ac2583" />

   <TemplateRules operator="and">

    <TemplateRule Description="Structural members and connections assigned to the analysis model." />

   </TemplateRules>

  </Concept>

 </Concepts>

</ConceptRoot>

Concept inheritance

#	Concept	Template	Model View
IfcRoot
	Identity	Software Identity	General Usage
	Revision Control	Revision Control	General Usage
IfcObjectDefinition
	Classification Association	Classification Association	General Usage
	Assignment to Product	Assignment to Product	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 with Override	Property Sets with Override	General Usage
IfcSystem
	Property Sets	Property Sets for Objects	General Usage
	System Element Attributes	System Element Attributes	General Usage
IfcStructuralAnalysisModel
	Aggregation	Aggregation	General Usage
	Group Assignment	Group Assignment	General Usage

Formal representations

XML Specification

 <xs:element name="IfcStructuralAnalysisModel" type="ifc:IfcStructuralAnalysisModel" substitutionGroup="ifc:IfcSystem" nillable="true"/>

 <xs:complexType name="IfcStructuralAnalysisModel">

  <xs:complexContent>

   <xs:extension base="ifc:IfcSystem">

    <xs:sequence>

     <xs:element name="OrientationOf2DPlane" type="ifc:IfcAxis2Placement3D" nillable="true" minOccurs="0"/>

     <xs:element name="LoadedBy" nillable="true" minOccurs="0">

      <xs:complexType>

       <xs:sequence>

        <xs:element ref="ifc:IfcStructuralLoadGroup" maxOccurs="unbounded"/>

       </xs:sequence>

       <xs:attribute ref="ifc:itemType" fixed="ifc:IfcStructuralLoadGroup"/>

       <xs:attribute ref="ifc:cType" fixed="set"/>

       <xs:attribute ref="ifc:arraySize" use="optional"/>

      </xs:complexType>

     </xs:element>

     <xs:element name="HasResults" nillable="true" minOccurs="0">

      <xs:complexType>

       <xs:sequence>

        <xs:element ref="ifc:IfcStructuralResultGroup" maxOccurs="unbounded"/>

       </xs:sequence>

       <xs:attribute ref="ifc:itemType" fixed="ifc:IfcStructuralResultGroup"/>

       <xs:attribute ref="ifc:cType" fixed="set"/>

       <xs:attribute ref="ifc:arraySize" use="optional"/>

      </xs:complexType>

     </xs:element>

     <xs:element name="SharedPlacement" type="ifc:IfcObjectPlacement" nillable="true" minOccurs="0"/>

    </xs:sequence>

    <xs:attribute name="PredefinedType" type="ifc:IfcAnalysisModelTypeEnum" use="optional"/>

   </xs:extension>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


ENTITY IfcStructuralAnalysisModel

 SUBTYPE OF (IfcSystem);

  PredefinedType : IfcAnalysisModelTypeEnum;

  OrientationOf2DPlane : OPTIONAL IfcAxis2Placement3D;

  LoadedBy : OPTIONAL SET [1:?] OF IfcStructuralLoadGroup;

  HasResults : OPTIONAL SET [1:?] OF IfcStructuralResultGroup;

  SharedPlacement : OPTIONAL IfcObjectPlacement;

 WHERE

  CorrectPredefinedType : (PredefinedType <> IfcAnalysisModelTypeEnum.USERDEFINED) OR

  ((PredefinedType = IfcAnalysisModelTypeEnum.USERDEFINED) AND EXISTS (SELF\IfcObject.ObjectType));
END_ENTITY;

 EXPRESS-G diagram

	Statisches Modell
	Structural Analysis Model
	Modèle d'analyse structurelle

Item	Change	Description
IFC2x3 to IFC4 4.0.0.0
IfcStructuralAnalysisModel
OwnerHistory	MODIFIED	Instantiation changed to OPTIONAL.
SharedPlacement	ADDED
IFC4x2 to IFC4x3_RC1
IfcStructuralAnalysisModel
ServicesFacilities	ADDED