IfcQuantityTime

IfcQuantityTime是一个元素数量，它定义了一个时间度量，以提供与元素相关的时间属性。它通常由测量方法给出的特定测量规则下元素的配方信息给出。

示例：为墙浇注混凝土所需的时间量作为配方信息中人工部分的时间量给出。

IFC2x2中增加的新实体。

Formal Propositions

Rule	Description
WR21	If a unit is given, the unit type shall be time unit.
WR22	A valid weight quantity shall be greater than or equal to zero.

 

Attribute inheritance

#	Attribute	Type	Cardinality	Description	C
IfcPhysicalQuantity
1	Name	IfcLabel	[1:1]	Name of the element quantity or measure. The name attribute has to be made recognizable by further agreements.	X
2	Description	IfcText	[0:1]	Further explanation that might be given to the quantity.	X
	HasExternalReferences	IfcExternalReferenceRelationship @RelatedResourceObjects	S[0:?]	Reference to an external reference, e.g. library, classification, or document information, that is associated to the quantity.	X
	PartOfComplex	IfcPhysicalComplexQuantity @HasQuantities	S[0:1]	Reference to a physical complex quantity in which the physical quantity may be contained.	X
IfcPhysicalSimpleQuantity
3	Unit	IfcNamedUnit	[0:1]	Optional assignment of a unit. If no unit is given, then the global unit assignment, as established at the IfcProject, applies to the quantity measures.	X
IfcQuantityTime
4	TimeValue	IfcTimeMeasure	[1:1]	Time measure value of this quantity.	X
5	Formula	IfcLabel	[0:1]	A formula by which the quantity has been calculated. It can be assigned in addition to the actual value of the quantity. Formulas could be mathematic calculations (like width x height), database links, or a combination. The formula is for informational purposes only.	X

 

EXPRESS Specification

ENTITY IfcQuantityTime
 SUBTYPE OF (IfcPhysicalSimpleQuantity);
  TimeValue : IfcTimeMeasure;
  Formula : OPTIONAL IfcLabel;
 WHERE
  WR21 : NOT(EXISTS(SELFIfcPhysicalSimpleQuantity.Unit)) OR (SELFIfcPhysicalSimpleQuantity.Unit.UnitType = IfcUnitEnum.TIMEUNIT);
  WR22 : TimeValue >= 0.;
END_ENTITY;