Connecting Sections

Model Reference Manual

When a Section is connected manually, the relevant End Cutting Plane of the Section (DRNS/DRNE) is superimposed on the Cutting Plane (CUTP) of the connecting Joint. This requires that the direction and through point of the Section have been correctly specified; that is, that the correct end points are on an extension of the Section’s Neutral Axis.

In cases of misalignment, the Section’s position and orientation are given highest priority. Thus, connecting a Section will not cause the Section to move or rotate. The Joint will be aligned with the Section, if possible (but see the FREE option, below).

When the connection is made, the connection cross-references between the Section and the Joint are set. That is, the JOIS/JOIE of the Section and the CREF of the Joint are matched. Further, the relevant Connection Type attribute of the Section (CTYS or CTYE) is set to point to the Attached Connection Type attribute (CTYA) of the Catalogue Joint.

The FREE option allows the existing joint position to remain fixed, and the POSS and/or POSE of the section to be adjusted. This may cause the section to be displaced sideways, or its direction to rotate. It may also cause SNODEs and FITTINGs along the section to be displaced (even with RECALCULATE).

When the connection has been made, the corresponding Start or End Point of the Section (POSS/POSE) is calculated from the intersection of the Z axis of the Section with the new Cutting Plane which passes through the end of the Joint’s JLIN.

The RECALCULATE option causes the positions of elements which are members of a Section to be recalculated so that they remain in the same positions if the Section is moved. For example, the ZDIS defining the position of a Secondary Node would be recalculated if the POSS (from which ZDIS is measured) were moved as a result of a CONNECT command, so that the SNOD remained unmoved.

If both RECALCULATE and FREE are specified, the position of FITTINGs and SNODEs along the section are recalculated to be as close as possible to their original positions.


Examples:
CONN END TO /SJOINT3	Where the current element is a Section.
CONN WITH START OF /BEAM1	Where the current element is a Joint.
CONN START TO /PJOIN2 RECALC	Connects the start of the current Section without moving the positions of any secondary elements owned by the Section.

Command Syntax:

At Section level:

>- CONnect -+- STart -.
            |         |
            ‘- ENd ---+- FREE -.
                      |        |
                      ‘--------+- TO  <gid> -+- RECALCulate -.
                                             |               |
                                             ‘---------------+->

where <gid> identifies a Joint.

At Joint level:

>-- CONnect WITH --+-- STart --.
                   |           |
                   ‘-- ENd ----+-- OF  <gid> -->

where <gid> identifies a Section.