**impose_nodal_dof_from_transfer#

Description#

This boundary condition imposes degrees of freedom (DOF) or nodal reaction forces over a node set (nset) that bas been transfered from another problem with the same nset.

Note

This boudary condition is usually used for weak coupling problems requiring the transfer of nodal dof (or nodal reaction forces), at each time increment, to another part of the problem that share the same nset with the first part.

Syntax#

**impose_nodal_dof_from_transfer \(~\,\) *file file_name \(~\,\) *nset nset_name [ *reaction \(~\,\) *dof R_dof_name … R_dofN_name ] [ *dof dof_name … dofN_name ]

file_name

name of the file without extension in which node kinematic (e.g U1, U2) (resp. nodal reaction forces (e.g RU1, RU2) ) to be applied are defined.

nset_name

name of the nset on which nodal dofs/reactions are applied.

reaction

flag used to impose nodal reaction forces, obtained from the other problem, in the opposite direction in order to have equilibrium (\(F_1 + F_2 =0\)).

dof_name

is the nodal dof (e.g U1, U2).

R_dof_name

is the nodal reaction forces (e.g RU1, RU2).

DOFs’ names dof_name and nodal0 reaction forces R_dof_name are listed in the problem.ut file.

Example#

In this example, a rectangle(1x3) is split up in two parts :

  • left is made of hard material.

  • right is made of soft material.

We use a Dirichlet-Neumann coupling.

calcul_mono.inp presents the same problem in a ‘not coupled’ manner

The example can be found in $Z7PATH/TESTS/Coupled_test/INP/MechMech_DN.inp.

In $Z7PATH/TESTS/Coupled_test/INP/MechMech_DN, there are two files meca_droite.inp and meca_gauche.inp that desmonstrate the use of this BC with nodal dof and nodal reaction forces.

BC with nodal dof : file meca_droite.inp

***bc
 **impose_nodal_dof_from_transfer
  *file MechMech_DN/kinematic_from_gauche
  *nset interface_d
  *dof U1 U2

BC with nodal reaction forces : file meca_gauche.inp

***bc
 **impose_nodal_dof_from_transfer
  *file MechMech_DN/reaction_from_droite
  *nset interface_g
  *reaction
  *dof  RU1 RU2

Note

There are three files with the same prefix file_name that are generated with the command **transfer node_kinematic_at_nset (resp. **transfer node_reaction_at_nset), but with different extensions : file_name.catalog, file_name.initial and file_name.final.

  • file_name.catalog is a file that contains the initial time, the final time and the mesh used. The initial time is the time of the previous increment. The final time is the time at the end of the ongoing increment.

  • file_name.initial is a file that contains the values of the DOFs (resp. R_DOFs) of the nset specified in the BC at the initial time.

  • file_name.final is a file that contains the values of the DOFs (resp. R_DOFs) of the nset specified in the BC at the final time.