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User-defined section shape

A user-defined shape is available in addition to the straight, catenary, arc upper and arc Lower line section shapes. This user-defined shape allows to specify any section shape through its coordinates as a function of the curvilinear abscissa. You may use either an ASCII file or the equilibrium deformed shape of a line calculated from a previous static simulation. The nodes coordinates will be used to draw the line in the 3D view window.

In the Shape list-box, the selection of the item User-defined opens an Edit & Browse control from which you may select the data file.

The file format for the ASCII file is illustrated below. It consists in one line with 0 or 1 and an arbitrary number of lines. The values 0 or 1 allows to specify whether the curvilinear abscissa and coordinates given in the text file refer to un-scaled or scaled values. Un-scaled values for the curvilinear abscissa are expressed in meters and must be input in the file when 0 is specified, whereas scaled values with curvilinear abscissa varying between 0 and 1 must be input to the file when 1 is specified.

Every following lines are associated with a curvilinear abscissa and contains 7 values : the curvilinear abscissa and the node coordinates for translations and rotational degrees of freedom. The three last columns corresponding to rotational degrees of freedom may be omitted.

0 or 1
Abscissa(1) X(1) Y(1) Z(1) RX(1) RY(1) RZ(1)
Abscissa(2) X(2) Y(2) Z(2) RX(2) RY(2) RZ(2)
Abscissa(3) X(3) Y(3) Z(3) RX(3) RY(3) RZ(3)
...
Abscissa(N) X(N) Y(N) Z(N) RX(N) RY(N) RZ(N)

The position of the nodes to be displayed in the 3D view window is computed through interpolation based on the geometric line defined in the ASCII file. The values taken from the file are factored by the total length of the section when scaled values are specified.

Note

A shape file is relative to the whole line but the user may want to define straight or catenary or another shape for one or several sections in the line. Then the file is no longer used for these sections.

Whatever the type specified in the file: the last node of each section is the primary point given by the user in the line edition panel. As the interpolated computed position of this node may not correspond to the position of this primary point, the next-to-last node position is computed and the last node position is set to what specified (primary point position).