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10. Construction

*Construction defines auxiliary geometric entity, called construction, which is used for modelling. Each construction must have a unique name, and duplicate names are not allowed.

*Construction

Define auxiliary geometric entity 

*Construction, TYPE=type Name=name
 ...
Keyword line
  • TYPE=type: Type of construction
    • Spline: Parametric spline
    • Line: Set of construction lines
  • Name=name: Name of the construction

*Construction, Type=Spline

Define spline

*Construction, Type=Spline, Name=name
 x,y,z[,pointType]
 ...
First dataline and subsequent datalines
  • x,y,z: Coordinates of sampling points (required)
  • pointType: Connection condition for intermediate sampling points (optional); CC, FF, FC, and CF are applicable. CC is default. Ignored at the start and end points.

A parametric spline is constructed using the given coordinates. Splines are used to define the shape of embedded line elements or when defining shapes in *Report, TYPE=LineSensor. At least two sampling points must be defined. The spline is constructed as a parametric cubic spline of the form (x(t), y(t), z(t)) using the provided sampling points. t is generated from the accumulated secant length of the given coordinates. The conditions imposed on the spline according to the pointType are as follows:

  • End points: Always curvature free
  • Intermediate points:
  • CC: No conditions imposed: slope and curvature continuity
  • FF: Curvature free + curvature free
  • CF: Slope continuity + right curvature free
  • FC: Left curvature free + slope continuity

The curve segment between sampling points is internally subdivided repeatedly until the segment length converges.

Example
*Construction, Type=Spline, Name=2spanTendon
  0,  0.         , 0.
 13, -0.8        , 0. 
 26,  0.19411765 , 0.
 30,  0.5        , 0.
 34,  0.19411765 , 0.
 47, -0.8        , 0.
 60,  0          , 0.

*Construction, Type=Spline, Name=curve
 20,  0,  0
 11,  0,  0,  FC
 10,  1,  0,  CF
 10, 19,  0,  FC
  9, 20,  0,  CF
  1, 20,  0,  FC
  0, 19,  0,  CF
  0, 11,  0,  FC
  1, 10,  0,  CF
 19, 10,  0,  FC
 20,  9,  0,  CF
 20,  0,  0,

*Construction, Type=Line

Define a construction line.

*Construction, Type=Line, Name=name
 x0, y0, z0, x1, y1, z1
 ...
Keyword line
  • Name=name: Name.
First dataline and subsequent datalines
  • x0, y0, z0, x1, y1, z1: Start point and end point

The construction line is not used in the analysis functionality. It is a command used to store additional information needed for visualization.

Example
*Construction, Type=Line, Name=name
 0, 0,0, 10, 0, 0
 0,10,0,  1, 0, 0