Structural Pointsets (PTSSET)

A PTSSET is a collection of P-line elements (PLINE). P-lines are used in the Catalog by Profiles and Joints. P-lines are used in the design process to position and orientate Sections (derived from Profiles) and Joints.

D and 3D Views of a P-line

A P-line is the structural counterpart of a P-point. It is a line which runs the full length of a Component parallel to its Z axis. Viewed in the XY plane, it appears as a point. This point is its position. A P-line also has a direction. This is not the direction of the line itself (which is always parallel to the Z axis of the Component), but a direction from the line in the XY plane. The position and direction are defined in XY coordinates only. the D and 3D Views of a P-line image shows a two-dimensional view and a three-dimensional view of a P-line on the top of a Section.

P-lines may be used in Paragon to define the position and orientation of the 2D primitives in a Structural Geomset which make up a Profile. They cannot be used to position and orientate the 3D primitives which make up a Joint.

One of the P-lines in a Structural Pointset must be designated as the neutral axis p-line. This is used in Model for positioning and orientating the Component. (The neutral axis is the line where there is no stress in bending, and about which the Component bends.) A P-line is designated as the neutral axis by setting the neutral axis reference attribute (NAREF) of the Structural Pointset to the name of the P-line.

A PLINE has no member elements and has the following attributes:

• PKEY - the P-line identifier key

• PX,PY - the X, Y coordinates of the P-line

• PLAXI - the axis of the P-line, defining its direction

• LEVEL - the drawing level range attribute

• CLFLA- the centerline drawing flag attribute

• TUFLA - the tube drawing flag attribute

• DESC - a textual description of the Pline

• PURP - the purpose of the Pline

PKEY is a word attribute which identifies the P-line. It is equivalent to the NUMB attribute of a P-point. PLAXI is a direction, equivalent to the PAXI attribute of a P-point.

PKEY must be set as a word. PLAXI must be set as a direction - refer to Defining an Axis for details. PX and PY may be set as values or in terms of parameters. The classes of parameter which may be used depend on whether the P-line is used by a Profile or by a Joint - refer to Parameters for further information. Manipulating the Catalog Database using Paragon gives examples of setting these attributes.

The settings of LEVEL, CLFLA and TUFLA and the use of the REPRESENTATION command affect whether or not the P-line is drawn by Paragon. LEVEL is a pair of numbers specifying a range and CLFLA and TUFLA are set to TRUE or FALSE (corresponding to ‘on’ or ‘off’ respectively). The way in which LEVEL, TUFLA and CLFLA and the REPRESENTATION settings interact is discussed in P-point and P-line Representation. (The settings of LEVEL, CLFLA and TUFLA also affect whether or not the P-line is drawn in Model.)

The primitives in the Geomsets also have LEVEL, CLFLA and TUFLA attributes, which affect whether or not they are drawn in Paragon and Model.

Note:
A P-line has its own set of axes, which are used in the design process (not in Paragon). Refer to Positioning and Orientating Using P-lines for further information.