smallStrainIncUpdated

Description

This class olves for incremental displacement DD in an updated configuration (i.e. the mesh is updated at the start of the time step), but employs the small-strain approximation.

This means that the strain tensor is still assumed to be linear linear, i.e.:

\[ \begin{aligned} \epsilon = \frac{1}{2} (\nabla D + \nabla^T D) \end{aligned} \]

and that while the configuration is updated at every time step, the geometric non-linearity between start of time-step and end-of time step configuration is neglected, i.e. the start of time-step or reference configuration and updated or end of time-step configuration are considered to be the same (within that time-step).

---

Options

As a mechanicsSubSolver class, smallStrainIncrementalUpdated allows the user to specify a few additional parameters in the mechanicsOptions sub-dictionary located within the solverDict.

Parameters in mechanicsOptions:

forceSummary	It prints a summary of boundary-forces at each iteration. It is set to false by default.
cylindricalStress	Creates cylindrical stress, strain and displacement field. It is useful for visualization and data-analysis purposes. It is set to false by default.
sphericalStress	Creates spherical stress, strain and displacement field. It is useful for visualization and data-analysis purposes. It is set to false by default.
updateMesh	Decides wheter the configuration is updated at every time-step or not. It is set to true by default. If set to false, the solver becomes effectively a small strain incremental solver (with no update).
RhieChowCorrection	Apply a correction to the explicit component of the divergence of the stress, similar to a Rhie & Chow correction, to stabilize the momentum equation. It is set to true by default unless the multiMaterialCorrection is activated. It is strongly suggested to use a RhieChowCorrection unless the multiMaterialCorrection itself is activated.
RhieChowScaleFactor	Scaling factor for the RhieChowCorrection. A value of 1 is used by default and corresponds to applying the full correction. A value of 0 applies no correction at all.
multiMaterialCorrection	Additional subdictionary that applies a custom discretization scheme for both the implicit and explicit components of the stress divergence. This means that the gradient scheme for the stress and the laplacian scheme for the displacement fields are neglected. The correction is not activated by default.

---

Usage

Here is a code snippet of the solverDict to be used for activating the smallStrainIncrementalUpdated mechanics solver class:

mechanicsSolver smallStrainIncrementalUpdated;

mechanicsOptions
{
    // Print summary of boundary-forces at each iteration
    forceSummary false;

    // Creates cylindrical stress and displacement field
    cylindricalStress false;

    // Creates spherical stress and displacement field
    sphericalStress false;

    // Update the mesh at every time-step
    updateMesh on;

    // Apply RhieChowCorrection to stabilize momentum equation (it should
    // be activated in most situations)
    RhieChowCorrection true;

    // Optional subDict for multi-material cases (it has priority over
    // RhieChowCorrection when activated)
    multiMaterialCorrection
    {
        // other correction types are possible
        type none;
    }
}