Selecting nodes for applying boundary conditions

[Deternanna]

Hi everybody,
It's me again. Today I have an issue with selecting nodes using the mapdl.nsel and then applying boundary conditions to those nodes. My issue is that between me selecting different nodes with .nsel, the boundary conditions that I have already applied seem to disappear. I want to do the following to the nodes, where I select them right before applying the boundary condition,

# Apply locking in z-direction
mapdl.d("ALL", "UZ")

# Apply locking in x-direction for nodes at x_max
mapdl.nsel("S", "LOC", "X", x_max)
mapdl.d("ALL", "UX")

# Apply locking in y-direction for nodes at y_min
mapdl.nsel("S", "LOC", "Y", y_min)
mapdl.d("ALL", "UY")

# Apply locking in x-direction for nodes at x_min
mapdl.nsel("S", "LOC", "X", x_min)
mapdl.d("ALL", "UX")

# Apply force of 1 N in negative y-direction at nodes at y3
mapdl.nsel("S", "LOC", "Y", y3)
mapdl.f("ALL", "FY", -1)

I hope you guys can see an obvious mistake I am making, and hope you can help me fix it.
Thanks in advance!

[mikerife]

Hi @Deternanna there are no mistakes in the PyMAPDL code...asuuming the x_min etc values are correct. So, what do you mean by disappear? After solving do the results show that the load and boundary conditions are there? What leads you to think that the BCs are not correct?

[Deternanna]

If I just run this code as it is, this is the only boundary condition that gets applied. Which is locking of the displacement in the x direction at the y3 value.

I have tried applying them individually and I can see that they fit with what I want, but as soon as I apply a new selection and boundary condition, it deletes the previous selection and boundary conditions. Does that make sense?

[Deternanna]

Okay I found the answer myself, you apparently have to add,

mapdl.nsel('ALL')

For it to select all nodes before going into the solving stage, otherwise it only remembers the conditions you put unto the latest selected nodes.