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In Preprocessor of APDL, I have built areas which are meshed with shell element and lines meshed with beam elements.

I have assigned Sections to Beam elements but when I view them their cross sections are flipped due to Line normals flipping.

I want all lines to become aligned to that specific Coord. And I don't want to manually pick the lines.

LDIR is not working for me as it reverses all the lines together leaving the issue as it is.

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Shell element orientation is defined by normal, because it only has two faces. However, beam element has a section, whose orientation has to be aligned. Switching line orientation might flip the section, but not align it into a desired orientation. The section is basically 2D and it has a principal axis, which can be aligned either using coordinate system axis or using a point (or a node) which is not lying on the element axis. Here is a video with instructions how to do so.

You may also benefit from looking into ANSYS Mechanical APDL Modeling and Meshing Guide, part Generating a Beam Mesh With Orientation Nodes.

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  • $\begingroup$ Line normals are set by ANSYS during line creation process even before shell mesh creation. Along a particular Axis direction, ANSYS assigns Positive or Negative Axis direction on its own. I just want it to follow Only either Positive or Only negative (base on the chosen Coord Axis). $\endgroup$
    – Rehan Khan
    Jan 15 at 7:27
  • $\begingroup$ The line orientation might depend on the order of point picking during the creation (if created using points). If the area is a directly created rectangle, the lines orientations are such that they go around the area in the loop. When dealing with non-planar areas, individual line orientation might affect resulting area shape. $\endgroup$ Jan 15 at 8:50
  • $\begingroup$ Lines are automatically created through Areas which are planar rectangle. Yes, they belong to loops and hence turn opposite in juxtaposed loops. Now, we want to modify their normals to get aligned to any particular Axis we give to Co-Axial lines. That is the main issue. $\endgroup$
    – Rehan Khan
    Jan 19 at 21:42
  • $\begingroup$ I believe you are mixing two issues together. One is line orientation and the other is beam section alignment. Every line has an orientation and you can flip it similarly to a shell normal. However, when you want to align beam section, you need to specify that differently. One way is shown in the video, and I think it can also be done during meshing. What you need for this is a node or a point not lying on the line (mathematical), so a normal to the APDL line (mathematical segment) can actually by defined. $\endgroup$ Jan 19 at 22:40
  • $\begingroup$ Yes. Section orientation is defined by that KP but it is governed first by Line Direction. Thats why i have to manually change Line Normals to Align them to become Unidirectional. Currently, ANSYS generates lines that are Co-linear but flipped resulting in Sections flipped and finally requiring me manually Re-orientate each line. $\endgroup$
    – Rehan Khan
    Jan 20 at 8:43

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