# PLE forum

Full Version: Displacements in the LOCAL coordinate system
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Last I had a project to calculate a pipeline number 1 with Ple4Win with a certain condition. A other pipeline number 2 was lying next to the pipeline number 1 and the distance between these pipelines would be 100 mm. The condition was therefore that the horizontal displacement (U-Y-LOCAL) of the pipeline number 1 in Local Y-direction should not exceed 100 mm (preferable value: max. 80 mm).
See attachment, the displacements U-X, U-Y, and U-Z in Function 5: Pipeline Behaviour are all given in the Global direction. My wish is to show these displacements not in the Global coordinate system, but rather in the Local coordinate system. Why? Because:
The Global displacements U-X, U-Y and U-Z are today hardly used as results, where to my findings Local displacements are more important than the Global displacements. The actual information of U-X, U-Y and U-Z can only be used for a straight pipeline. Today the pipelines are more complex with horizontal bends.
A SingleGraph of the Global displacements does not show the real displacement of the pipeline after a horizontal bend. Even though, after the pipeline has had a horizontal bend, there is a actually way to calculate the displacements of U-Y and U-Z in Local direction by making further calculation to calculated the Y- and Z-components of U-LAT. But why do that if the displacements U-X, U-Y, and U-Z could be shown in Local direction.
For a Global view of the displacements the user can see the schematics of the pipeline.
And with U-Y given in Local direction and by making a SingleGraph I could see directly if 80 mm of 100 mm has been exceeded. This is also important as proof for clients.
If after this you still think that Global displacements are more important than Local displacements, then I would like in DISPLAC a way for the user to see U-X, U-Y and U-Z in Local or / and Global direction.
Displacements in the local coordinate system are shown in the columns U-AX and U-LAT. As the help file explains:

U-AX:
Displacement of node (n) in axial (x) direction

PHI-AX:
Rotation of node (n) around axial (x) direction

U-LAT:
Displacement of node (n) in lateral direction (y-z plane)

PHI-LAT:
Angle of lateral displacement of node (n) (around x-axis)

(Displacements in axial and lateral direction are oriented according the LOCAL node coordinate system.)

This should be sufficient in your case. If not, please explain what other data you would like to see.
I wanted to see U-X, U-Y and U-Z in the LOCAL coordinate system rather then showing U-X, U-Y and U-Z in the GLOBAL coordinate system.

With a given U-LAT with PHI-LAT (LOCAL) the displacement perpendiculair to a pipeline in the xy-plane in the LOCAL coordinate system can be determined in excel by factorizing these values and then maximazing the values.

A displacement perpendiculair to a pipeline (LOCAL) has more importance in the case where you have two pipelines parallel to each other. The horizontal displacement of the new pipe (LOCAL !) should always be less then the distance between these pipelines. With the icoon 'Show maxima & minima' in a table with U-X, U-Y and U-Z in a LOCAL coordinate system I can see directly if the distance between the pipeline has been exceeded.

In PLE4Win the displacements are shown in the GLOBAL coordinate system. If you have a pipeline like in the image as shown here below (attachment), the U-X, U-Y and U-Z in the LOCAL coordinate system is not the same as the U-X, U-Y and U-Z in the GLOBAL coordinate system.