![]() | Statisches Modell: Idealisierung zur Berechnung der Auflagerreaktionen und des Kräfteverlaufs |
![]() | Structural Analysis Model |
![]() | Modèle d'analyse structurelle |
Item | SPF | XML | Change | Description | IFC2x3 to IFC4 |
---|---|---|---|---|
IfcStructuralAnalysisModel | ||||
OwnerHistory | MODIFIED | Instantiation changed to OPTIONAL. | ||
SharedPlacement | ADDED |
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:
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.
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:
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 | Type | Cardinality | Description | B |
---|---|---|---|---|---|
6 | PredefinedType | IfcAnalysisModelTypeEnum | [1:1] | Defines the type of the structural analysis model. | X |
7 | OrientationOf2DPlane | - | This attribute is out of scope for this model view definition and shall not be set. | ||
8 | LoadedBy | IfcStructuralLoadGroup | S[1:?] | References to all load groups to be analyzed. | X |
9 | HasResults | IfcStructuralResultGroup | S[1:?] | References to all result groups available for this structural analysis model. | X |
10 | SharedPlacement | - | This attribute is out of scope for this model view definition and shall not be set. |
Rule | Description |
---|---|
HasObjectType | The attribute ObjectType shall be given if the predefined type is set to USERDEFINED. |
# | Attribute | Type | Cardinality | Description | B |
---|---|---|---|---|---|
IfcRoot | |||||
1 | GlobalId | IfcGloballyUniqueId | [1:1] | Assignment of a globally unique identifier within the entire software world. | X |
2 | OwnerHistory | IfcOwnerHistory | [0:1] |
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. | X |
3 | Name | IfcLabel | [0:1] | 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 | [0:1] | 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). | ||
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). | 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. | ||
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). | 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). | 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 | - | This attribute is out of scope for this model view definition and shall not be set. | ||
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. | 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. | X | |
IfcGroup | |||||
IsGroupedBy | IfcRelAssignsToGroup @RelatingGroup | S[0:?] | Reference to the relationship IfcRelAssignsToGroup that assigns the one to many group members to the IfcGroup object. | X | |
IfcSystem | |||||
IfcStructuralAnalysisModel | |||||
6 | PredefinedType | IfcAnalysisModelTypeEnum | [1:1] | Defines the type of the structural analysis model. | X |
7 | OrientationOf2DPlane | - | This attribute is out of scope for this model view definition and shall not be set. | ||
8 | LoadedBy | IfcStructuralLoadGroup | S[1:?] | References to all load groups to be analyzed. | X |
9 | HasResults | IfcStructuralResultGroup | S[1:?] | References to all result groups available for this structural analysis model. | X |
10 | SharedPlacement | - | This attribute is out of scope for this model view definition and shall not be set. |
Structural analysis of bridges involves analytical models that approximate the physical behavior of specific bridge geometry. Such analytical models may make use of curve members, surface members, and volumetric members. Finite element analysis may be applied, effectively reducing everything into a mesh of nodes and linear members. Within such structural model, load cases and combinations may be defined, with resulting stresses and displacements captured.
For the purposes of design plans, inclusion of full structural analysis information may not be necessary, however the resulting stresses and deflections at each member according to each load combination must be captured, to determine allowable loading during construction.
The specific plans for this example contain resulting shear and moments at locations along girder spans, and displacements from dead loads used to calculate camber ordinates. Additionally, the plans indicate the load cases and combinations.
![]() |
Figure 65 — Bridge structural reactions |
Group Assignment
The Group Assignment concept applies to this entity as shown in Table 80.
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Table 80 — IfcStructuralAnalysisModel Group Assignment |
Exchange | ![]() |
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Import | O | R | ||
Export | O | R |
Structural Analysis Model Attributes
The Structural Analysis Model Attributes concept applies to this entity.
Exchange | ![]() |
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---|---|---|---|---|
Import | O | R | ||
Export | O | R |
# | Concept | Model View |
---|---|---|
IfcRoot | ||
Software Identity | Bridge View | |
User Identity | Bridge View | |
Object Ownership | Bridge View | |
IfcObject | ||
Property Sets for Objects | Bridge View | |
IfcStructuralAnalysisModel | ||
Group Assignment | Bridge View | |
Structural Analysis Model Attributes | Bridge View |
<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="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:sequence>
<xs:attribute name="PredefinedType" type="ifc:IfcAnalysisModelTypeEnum" use="optional"/>
</xs:extension>
</xs:complexContent>
</xs:complexType>
ENTITY IfcStructuralAnalysisModel
SUBTYPE OF (IfcSystem);
PredefinedType : IfcAnalysisModelTypeEnum;
OrientationOf2DPlane : OPTIONAL IfcStrippedOptional;
LoadedBy : OPTIONAL SET [1:?] OF IfcStructuralLoadGroup;
HasResults : OPTIONAL SET [1:?] OF IfcStructuralResultGroup;
SharedPlacement : OPTIONAL IfcStrippedOptional;
WHERE
HasObjectType : (PredefinedType <> IfcAnalysisModelTypeEnum.USERDEFINED) OR EXISTS(SELF\IfcObject.ObjectType);
END_ENTITY;