Flexible DFBI Motion Model Reference

The Flexible DFBI Motion model allows you to combine the solid stress solver with the DFBI module to model deformable DFBI bodies in FSI simulations.

For deformable DFBI bodies, the DFBI framework calculates the overall rigid motion of the body, while the solid stress solver calculates any body deformations. For more information, see Deformable DFBI Bodies.

Provided by [physics continuum] > Models > Optional Models
Example Node Path Continua > [Solid Physics Continuum] > Models > Flexible DFBI Motion
Requires Physics Models:
  • Optional Models: Solid Stress
Activates Region Inputs Flexible DFBI Motion Option. See Region Inputs.

Region Inputs

Applies to solid regions.

Flexible DFBI Motion Option
Available options:
  • DFBI - Deformable body—the solid region coincides with the whole DFBI body. The DFBI body motion has two components: the rigid motion computed by the DFBI module, and the non-rigid deformation computed by the solid stress solver.
  • DFBI - Partially deformable body—The solid region coincides with a component of the DFBI body. The solid component can undergo non-rigid deformations in response to the applied forces, while the rest of the DFBI body is assumed to be perfectly rigid.
  • DFBI - Deformable moving attachment—The solid region coincides with a moving component of the DFBI body. The solid component has prescribed rotation or translation motion and can undergo non-rigid deformations in response to the applied forces. The rest of the DFBI body is assumed to be perfectly rigid.

Motion Models Configuration

The required motion models depend on the selected Flexible DFBI Motion Option and FSI Coupling Method.

DFBI - Deformable body, DFBI - Partially deformable body
These options are only available for two-way coupling.
FSI Coupling Method Region Motion Description
Two-way Fluid region DFBI Morphing The boundaries of this region are moved according to the calculated 6-DOF rigid motion and morphed based on the solid deformations computed by the Solid Stress solver.
Solid region Superposition of the following motions:

6-DOF Body Motion > Solid Displacement

 The solid region follows the calculated 6-DOF motion and deforms due to the applied fluid loads.
DFBI - Deformable moving attachment
FSI Coupling Method Region Motion Description
One-way Fluid region Superposition of the following motions:

6-DOF Body Motion > [Rigid Motion]

 [Rigid Motion] can be either a Rotation or Translation motion. The fluid boundary does not require morphing as the effect of the solid deformations on the fluid are neglected. Both regions move according to the calculated 6-DOF motion and the prescribed rigid rotation or translation.
Solid region Superposition of the following motions:

6-DOF Body Motion > [Rigid Motion]
Two-way Fluid region DFBI Morphing The boundaries of this region are moved according to the calculated 6-DOF rigid motion and the prescribed rigid motion. Additionally, they are morphed based on the solid deformations computed by the Solid Stress solver.
Solid region Superposition of the following motions:

6-DOF Body Motion > [Rigid Motion] > Solid Displacement

 The solid region follows the calculated 6-DOF motion, has an additional prescribed rigid motion, and deforms due to the applied fluid loads.