6.1.4.2.2. Spline

It allows the user to create a curve that is composed of several user-defined points. At that time, in order to smooth the curve, the interpolation method is applied to the curve from the user-defined points.

The RecurDyn spline geometry is the cubic curve(polynomials of degree 3). If the curve is open, it’s a natural end condition. If the curve is closed, it’s a periodic end condition.

6.1.4.2.2.1. Modeling Options

The user can create a spline geometry by the following procedure.

  • MultiPoint (Open)

    • MultiPoint: Selects some points.

  • MultiPoint (Closed)

    • MultiPoint: Selects some point.

6.1.4.2.2.2. Properties

The user can modify the geometry information using the Spline Geometry property page.

Data Type

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Figure 6.49 Spline property page [Data type]

  • Number of Points: Shows the number of points that make up the spline geometry.

  • Points: A cubic spline is created interpolating these points.

  • Derivatives: Specify the first-order derivatives at the corresponding points. These are the direction of the derivatives.

  • Magnitudes: Specify the magnitudes of the corresponding derivatives.

  • Add: Adds a row to the end of the table.

  • Insert: Adds a new row to the selected row with the mouse cursor and moves the current and lower rows down.

  • Insert Mid: Adds a point centered between the selected point and the point directly above it to the row directly above it.

  • Delete: Deletes the selected row by the mouse cursor and moves the lower rows up.

  • Clear: Deletes all rows in the table.

  • Import: Imports the X, Y, and Z data pairs from a MAT file or a text file. In the case of the text file, the usage of the comma, the tab, and the space can be the delimiter between the three columns in the file. And when using the Excel file, the user can select the Tab-delimited text file output option or the CSV (Comma-Separated Values) file output option to save the Excel file which can be imported.

  • Export: Exports the X, Y, and Z data pairs to a MAT file or a text file.

  • Vertices at Points: Vertices are created at all points. If unchecked, vertices are not created on the continuous part.

  • Preview: Preview the points on the line to be created on Working Window.

File Type

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Figure 6.50 Spline property page [File type]

  • Reload: Reloads the file to the spline data in order to update the data when the user modified the file data.

  • Export: Exports the X, Y, and Z data pairs to a MAT file or a text file.