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4.2.2.1.2 Bloss Transition Segment

The Bloss transition segment is a special case of a fifth order spiral where the curvature rate of change is a cubic function and the terms are dependent on the length L measured from the inflection point. The parameter value is defined as the deflection i.e. bearing angle &Theta.

Only the cubic and quadratic terms are populated with the following values: QubicTerm = L/³√2 QuadraticTerm = L/√3

The following diagram shows the generic classes and relationships used when applying this concept.

%3 IfcCurveSegment IfcCurveSegment      LayerAssignment [0:1]      StyledByItem [0:1] 1. Transition [1:1]      UsingCurves [1:?] 2. Placement [1:1] 3. SegmentStart [1:1] 4. SegmentLength [1:1] 5. ParentCurve [1:1] IfcThirdOrderPolynomialSpiral IfcThirdOrderPolynomialSpiral      LayerAssignment [0:1]      StyledByItem [0:1] 1. Position [1:1] 2. CubicTerm [1:1] 3. QuadraticTerm [0:1] 4. LinearTerm [0:1] 5. ConstantTerm [0:1] IfcCurveSegment:ParentCurve1->IfcThirdOrderPolynomialSpiral:IfcThirdOrderPolynomialSpiral0 IfcLengthMeasure_0 IfcLengthMeasure IfcThirdOrderPolynomialSpiral:QubicTerm1->IfcLengthMeasure_0:IfcLengthMeasure0 IfcLengthMeasure_1 IfcLengthMeasure IfcThirdOrderPolynomialSpiral:QuadraticTerm1->IfcLengthMeasure_1:IfcLengthMeasure0
Figure 4.2.2.1.2.A

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2 contributor(s): bSI-BotstefkeB
Last change: Part of review for ISO and CEN/TC 442 by stefkeB on 2023-05-01T15:16:29+02:00

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