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IfcStructuralActivity

Definition from buildingSMART International: The abstract entity IfcStructuralActivity combines the definition of actions (such as forces, displacement, etc) and reactions (supports and deformations) which are specified by using the basic load definitions from theIfcStructuralLoadResource. It also uses the inherited capabilities for the definition of a location and a local coordinate system.

The differentiation between actions and reactions is realized by instantiating objects either from subclasses of IfcStructuralAction or IfcStructuralReaction respectively. They inherit commonly needed attributes from the abstract superclass IfcStructuralActivity. Possible dependencies between actions and reactions must be explicitly captured.

The use of the location and local coordinate system, given by ObjectPlacement, is optional as it is not always needed or useful.

NOTE: Not needed if the 'activity' acts on the whole element to which it is "connected" through an instance of IfcRelConnectsStructuralActivity and additionally, there is no eccentricity. It is not useful if the 'activity' acts on a building element because at this stage no geometrical abstraction is normally made.

NOTE: The definition of an 'activity' is normally used for the structural engineering domain, where the activity typically defines no own coordinate system but rather uses the coordinate system of the element on which it acts. Therefore the definition of a location and local coordinate system can be omitted by not assigning a value to ObjectPlacement, in these cases the local coordinate system shall correspond to the local coordinate system of the structural item or building element on which it acts.

In addition the IfcStructuralActivity defines the relation needed to associate actions and/or reactions to the IfcStructuralItem to which it applies.

HISTORY: New entity in Release IFC2x Edition 2.

EXPRESS specification:

ENTITY IfcStructuralActivity
ABSTRACT SUPERTYPE OF (ONEOF(IfcStructuralAction, IfcStructuralReaction))
SUBTYPE OF ( IfcProduct);
AppliedLoad  :  IfcStructuralLoad;
GlobalOrLocal  :  IfcGlobalOrLocalEnum;
INVERSE
AssignedToStructuralItem  :  IfcRelConnectsStructuralActivity FOR RelatedStructuralActivity;
END_ENTITY;

Attribute definitions:

AppliedLoad  :  Reference to the load resource, which is used to define the load type, direction and load values. The specified load types are provided in the IfcStructuralLoadResource presented at the end of this document.
GlobalOrLocal  :  Indicates if the load values are defined by using the local coordinate system or the global project coordinate system.
AssignedToStructuralItem  :  References to the IfcRelConnectsStructuralActivity relationship by which activities can be associated to structural representations.

Inheritance graph

ENTITY IfcStructuralActivity;
ENTITY IfcRoot;
GlobalId  :  IfcGloballyUniqueId;
OwnerHistory  :  IfcOwnerHistory;
Name  :  OPTIONAL IfcLabel;
Description  :  OPTIONAL IfcText;
ENTITY IfcObjectDefinition;
INVERSE
HasAssignments  :  SET OF IfcRelAssigns FOR RelatedObjects;
IsDecomposedBy  :  SET OF IfcRelDecomposes FOR RelatingObject;
Decomposes  :  SET [0:1] OF IfcRelDecomposes FOR RelatedObjects;
HasAssociations  :  SET OF IfcRelAssociates FOR RelatedObjects;
ENTITY IfcObject;
ObjectType  :  OPTIONAL IfcLabel;
INVERSE
IsDefinedBy  :  SET OF IfcRelDefines FOR RelatedObjects;
ENTITY IfcProduct;
ObjectPlacement  :  OPTIONAL IfcObjectPlacement;
Representation  :  OPTIONAL IfcProductRepresentation;
INVERSE
ReferencedBy  :  SET OF IfcRelAssignsToProduct FOR RelatingProduct;
ENTITY IfcStructuralActivity;
AppliedLoad  :  IfcStructuralLoad;
GlobalOrLocal  :  IfcGlobalOrLocalEnum;
INVERSE
AssignedToStructuralItem  :  IfcRelConnectsStructuralActivity FOR RelatedStructuralActivity;
END_ENTITY;