Area releases disconnect nodes

I’m trying to create a free edge between two areas. This works to some extent using the following code:

+prog aqua urs:1 $ Materials
MAT 11 E 35000 GAM 25 MUE 0.3
end

+prog Sofimshc urs:2 $ Geometry
    SYST 3D GDIV 100000 GDIR NEGZ
    CTRL MESH 1
    CTRL DELN 1
    CTRL TOPO 0
    CTRL EDRL 1

    SPT 1 X 0       Y 0    Z 0
    SPT 2 X 1000    Y 0    Z 0
    SPT 3 X 1000    Y 0    Z 1000
    SPT 4 X 0       Y 0    Z 1000

    SPT 5 X 2000    Y 0    Z 0
    SPT 6 X 2000    Y 0    Z 1000

    SAR 1 MNO 11  GRP 11  T 100
        SARB TYPE OUT NA 1 NE 2
        SARB TYPE OUT NA 2 NE 3 FIX PX
        SARB TYPE OUT NA 3 NE 4
        SARB TYPE OUT NA 4 NE 1

    SAR 2 MNO 11  GRP 11  T 100
        SARB TYPE OUT NA 2 NE 5
        SARB TYPE OUT NA 5 NE 6
        SARB TYPE OUT NA 6 NE 3
        SARB TYPE OUT NA 3 NE 2 !FIX PX

    SLN 1 NPA 1 NPE 5 FIX F ! This doesn't work on node 2
END

+prog sofiload urs:3 $ Load
    LC 1 TYPE 'None' TITL 'Vertical'
        LINE AUTO PROJ N TYPE PZZ P1 -10  X1 1000   Y1 0 Z1 1000 $$
                                  P2 -10  X2 2000   Y2 0 Z2 1000
end

+PROG ASE urs:4 $ ASE
    LC 1
end

Unfortunately, the bottom node which is shared by the right and bottom edge is released from it’s bottom boundary condition as well.

How to I force this node to adhere to the fixity I apply on node 2?

Hello

I am not sure what you are trying to do.
In order to understand the program behaviour you have to look at the relevant nodes (node 2 and 1002).
The boundary condition creates a new node for the corner of the surface (node nr. 1002) and this node is not fixed (Only node 2). Since you are only restricting the degree of freedom PX the node 1002 can move in the other directions.

So if you also want to fix this node, you have to create two different corner nodes for the two surfaces (and fix both) or you have to change the boundary condition of the node in a subsequent SOFiMSHA run.

+prog sofimsha urs:5
head
ctrl rest 2
syst rest
node 1002 FIX F
end 

Without knowing your goal, I can’t give you a optimal solution.

Best regards
Frederik Höller
Your SOFiSTiK Support Team

Sorry, but I believe I have stated what I’m trying to do?

"I’m trying to create a free edge between two areas. "

Anyway, your SOFIMSHA solution seems to do the trick.
However, in larger models this becomes impractical as sofistik creates and numbers these calculation nodes automatically, and I have no way of finding the generated nodes.

This leads the issue to be very similar to an earlier topic here: (https://forum.sofistik.de/t/add-releases-to-areas/1378)

According to this topic, I can explicitly define the edges in the areas using structural lines and then connecting those structural lines to eachother instead.

This however requires a lot of remodelling if all previous SARs are defined by nodes. So, is there a way force the SAR to use some explicitely defined nodes when creating the coupling instead of defining new nodes by it self?