.. _auto_curve_effective_voce:

*VOCE EXTRAPOLATION*
====================

Extrapolates a stress–strain curve beyond the last measured data point using the Voce hardening law σ = A − B·exp(−C·ε). Given fitted Voce parameters (A, B, C), an input curve, a target end strain, and a strain increment, it appends the analytically computed Voce continuation to the original curve. Use this worker to extend material flow curves for MAT_24 or similar plasticity cards up to large strains.

When to use
-----------

Classification: **process**.

Tagged: ``extrapolation``, ``flow_curve``, ``hardening``, ``mat_24``, ``material``, ``plasticity``, ``stress_strain``, ``voce``.

Inputs
------

.. list-table::
   :header-rows: 1
   :widths: 20 20 20 20 20 20

   * - Label
     - ID
     - Type
     - Default
     - Required
     - Description
   * - Curve In
     - curve_in
     - vector
     - —
     - 
     - Input true-stress / true-strain (or effective stress–plastic strain) curve to be extended; the extrapolation is appended starting from the last point of this curve.
   * - A
     - a
     - scalar
     - 0.0
     - 
     - Voce parameter A (saturation stress, same stress units as the curve, e.g. MPa); defaults to 0.0 — must be set to a physically meaningful value before use.
   * - B
     - b
     - scalar
     - 0.0
     - 
     - Voce parameter B (initial hardening amplitude, same stress units as A, e.g. MPa); defaults to 0.0 — must be set before use.
   * - C
     - c
     - scalar
     - 0.0
     - 
     - Voce parameter C (exponential decay rate, dimensionless strain⁻¹); defaults to 0.0 — must be set before use.
   * - Last Strain
     - last_strain
     - scalar
     - 1.0
     - 
     - Target end strain at which the Voce extrapolation terminates (dimensionless, e.g. 1.0 for 100 % plastic strain); default is 1.0.
   * - Increment
     - increment
     - scalar
     - 0.001
     - 
     - Strain step size used to generate the extrapolated points (dimensionless); default is 0.001 — reduce for smoother curves, increase to reduce output size.

Outputs
-------

.. list-table::
   :header-rows: 1
   :widths: 20 20 20 20

   * - Label
     - ID
     - Type
     - Description
   * - curve_effective_voce_output_1
     - curve_effective_voce_output_1
     - vector
     - Extended stress–strain curve consisting of the original input points followed by the Voce-extrapolated continuation up to last_strain, returned as an (ε, σ) vector pair.

Disciplines
-----------

- data.curve.transform
- engineering.material.calibration
- engineering.material.characterization

Runnable example
----------------

A runnable example is registered for this worker. Open the example workflow on the d3VIEW canvas: `/api/workflow/example?id=curve_effective_voce <https://www.d3view.com/api/workflow/example?id=curve_effective_voce>`_

.. raw:: html

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   Auto-generated from <code>transformation</code> schema. Worker id: <code>curve_effective_voce</code>. Schema hash: <code>b4532e9e215a</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
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