UBoundary
*UBoundary
<node set name>, <degree of freedom>, <value>
This command is used to prescribe user-defined boundary conditions on
nodes or node sets. If this command is used, numgeo expects the user
defined subroutine to be accessible (see here). Therefore, the user has to implement
the desired relation for the boundary condition using the predefined
user_boundary_conditions interface, create the corresponding shared
object user_boundary_conditions.so and place the object in the current
working directory. For the compilation of the subroutine, a shell script
is provided.
-
<node set name>= name of the node set to which the boundary condition is applied -
<degree of freedom>= the degree of freedom to be constrained. The following degrees of freedom can be modified:
| Degrees of freedom | Description |
|---|---|
u1 |
Displacement in x1-direction |
u2 |
Displacement in x2-direction |
u3 |
Displacement in x3-direction |
pw |
Pore-water pressure |
pa |
Pore-air pressure |
w1 |
Water displacement in x1-direction |
w2 |
Water displacement in x2-direction |
w3 |
Water displacement in x3-direction |
<value>= set this parameter equal to the value to be prescribed to the boundary condition. Notice that this value is interpreted as a reference value, which is multiplied with the value defined in the user subroutine. It is recommended to set this value to 1.0 and define the desired value directly in the user subroutine.