Position of the Profile

The position in space of a profile is specified by its trace curves that - for plane panels - are described in the coordinate system of the panel (or bracket) to which the profile belongs. In most cases the end point coordinates are computed by connection to other parts of the structure, that means, the trace curve is derived (secondary) information.

The line from end point 1 to end point 2 is called the mould line (or description line) of the profile.

For shell profiles the profile orientation is always explicitly defined. For stiffeners and flanges, the web (and the flange, if any) of the profile is supposed to be located to the left of the mould line. Thus, the orientation of the profile section is defined by selecting the direction of the mould line (or the order of the end profile).

For pillars, the description line is normally located in the symmetry line of the profile section. The orientation of the profile section is controlled by a separate data item.