# Structure element is created with new node when using by-nodeids

**URL:** <https://forum.itascainternational.com/t/structure-element-is-created-with-new-node-when-using-by-nodeids/687>\
**Category:** FLAC3D\
**Created:** [August 1, 2022, 1:41pm UTC](https://forum.itascainternational.com/t/structure-element-is-created-with-new-node-when-using-by-nodeids/687 "2022-08-01T13:41:32Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![ppk](https://avatars.discourse-cdn.com/v4/letter/p/7ab992/32.png) [@ppk](https://forum.itascainternational.com/u/ppk)\
**Post date:** [August 1, 2022, 1:41pm UTC](https://forum.itascainternational.com/t/structure-element-is-created-with-new-node-when-using-by-nodeids/687/1 "2022-08-01T13:41:32Z")

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I have tried to create two beam elements which sharing common node (id 1 at 0.0, 0.0, 0,0)  
However, new node (id 4) is created at (0.0, 0.0, 0,0) without any warning message

```auto
model new

structure node create (0.0, 0.0, 0.0)
structure node create (0.0, 0.0, 1.0)
structure node create (0.0, 0.0, -1.0)

structure beam create by-nodeids 1 2 ; snap on
structure beam create by-nodeids 1 3 ; snap on

```

FLAC3D version is 7.00.152

Additional question,  
How can I plot nodes before creating structural elements?

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<div class="post-metadata">

**Author:** ![ppk](https://avatars.discourse-cdn.com/v4/letter/p/7ab992/32.png) [@ppk](https://forum.itascainternational.com/u/ppk)\
**Post date:** [August 1, 2022, 2:11pm UTC](https://forum.itascainternational.com/t/structure-element-is-created-with-new-node-when-using-by-nodeids/687/2 "2022-08-01T14:11:00Z")

</div>

I have found answer from [Generation of Structural elements - #5 by FLAC3D\_GEO](https://forum.itascainternational.com/t/generation-of-structural-elements/543/5)

Is there any way to share node for different element ids? except for creating node to node link by using “structure node join …”  
If I use command “structure node join”, how many links(node to node, node to zone) can exist for one structural node?

Additional question,

**1. Please tell me the meaning of warning message below**  
“Axial direction of cable and piles or normal direction of liners and geogrids at shared node XX out of alignment by more than 30 degrees.”

**2. How can I plot nodes before creating structural elements?**

```auto
model new

structure node create (0.0, 0.0, 0.0)
structure node create (0.0, 0.0, 1.0)
structure node create (0.0, 0.0, -1.0)

structure beam create by-nodeids 1 2 id 1 ; snap on
structure beam create by-nodeids 1 3 id 1 ; snap on

```

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<div class="post-metadata">

**Author:** ![Moo](https://avatars.discourse-cdn.com/v4/letter/m/c4cdca/32.png) [@Moo](https://forum.itascainternational.com/u/Moo)\
**Post date:** [August 1, 2022, 4:16pm UTC](https://forum.itascainternational.com/t/structure-element-is-created-with-new-node-when-using-by-nodeids/687/3 "2022-08-01T16:16:33Z")

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cables and piles set up their interactions with zones relative to their node-local coordinate system (i.e. for cables rigid perpendicular to the elements and deformable parallel).  
These directions are averaged from the elements the cable node is connected to - for small angles this works out ok. For large differences in element orientation this can result in unexpected behavior.

For this reason we recommend that you do not share nodes between structural elements of different types (cables, shells, etc), or between cable structures meeting at a large angle. Instead use different nodes and create rigid links between them.

As for rigid connections - the rule is a node can only be rigidly connected to one thing in any given degree-of-freedom. A node can have any number of other deformable connections.  
Also, that said, node rigid connections can chain recursively an arbitrary number of times (node-\>node-\>node-\>zone for example).

Generally the STRUCTURE NODE JOIN will try to work that out for you, but if there is trouble or you want to be careful you can limit both the nodes selected to create attach conditions, and the target nodes they will attach to using the RANGE-TARGET keyword.

There is no explicit method to plot structural nodes that are not connected to any element. You can make the STRUCT VECTOR plot do this by using the STRUCT NODE INIT DISP (1,0,0) command and then plotting displacement vectors, just remember to reset them again to zero.

You could also copy all structural nodes to user defined scalars and then plot _them_, using the FISH fragment:  
[data.scalar.create(::struct.node.pos(::struct.node.list))]

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<div class="post-metadata">

**Author:** ![ppk](https://avatars.discourse-cdn.com/v4/letter/p/7ab992/32.png) [@ppk](https://forum.itascainternational.com/u/ppk)\
**Post date:** [August 2, 2022, 3:22am UTC](https://forum.itascainternational.com/t/structure-element-is-created-with-new-node-when-using-by-nodeids/687/4 "2022-08-02T03:22:11Z")

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Thank you for your answer.