Question regarding coordinates received by uboun.f subroutine

Hey everyone,

I have a simple question regarding the subroutine for user-defined boundary values (uboun.f). That subroutine receives the coordinates of the node(s) on which the boundary condition(s) is (are) applied. Are those the node’s coordinates in the reference configuration or the node’s coordinates in the spatial configuration?

I’d appreciate it if someone could clarify this.


This subroutine uses the coords variable which should contain the current coordinates of the nodes - if geometric nonlinearity is enabled, they will be updated, otherwise, they will keep their original values.

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That was exactly what I wanted to know. Thanks!

Related questions:

  • In a case with geometric nonlinearities, would it be possible the provide uboun.f with the node’s original values?
  • This one is slightly off-topic but in a way related to the previous ones: when specifying a local cylindrical coordinate system with *TRANSFORM, imposed displacements in the 2nd degree of freedom (tangential) must be expressed in radians, correct?


This would likely require quite significant modification of the source code.

Yes, the unit will be radian in such a case.

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Understood. Thanks again!