.. _auto_curve_effective_hocket_sherby:

*HOCKET SHERBY EXTRAPOLATION*
=============================

Extrapolates a stress–strain curve beyond its measured range using the Hockett–Sherby hardening law: σ = A − (A − B)·exp(−C·εⁿ). Given an input curve and the four model parameters (A, B, C, H), the worker generates a smooth extrapolated flow-stress curve up to a user-defined maximum strain. Use this worker to extend experimentally measured material curves for large-deformation plasticity inputs.

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

Classification: **process**.

Tagged: ``curve-fitting``, ``extrapolation``, ``flow-stress``, ``hardening``, ``hockett-sherby``, ``mat_24``, ``material``, ``plasticity``.

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 stress–strain curve (vector of strain–stress pairs) to be extrapolated; if omitted the worker generates the Hockett–Sherby curve purely from the parameter set.
   * - A
     - a
     - scalar
     - 0.0
     - 
     - Hockett–Sherby parameter A — saturated (ultimate) flow stress in the same stress units as the output curve (default 0.0; must be set to a physically meaningful value).
   * - B
     - b
     - scalar
     - 0.0
     - 
     - Hockett–Sherby parameter B — initial flow stress at zero plastic strain in the same stress units as the output curve (default 0.0; must be set to a physically meaningful value).
   * - C
     - c
     - scalar
     - 0.0
     - 
     - Hockett–Sherby parameter C — rate constant controlling the curvature of the hardening transition (dimensionless; default 0.0).
   * - H
     - h
     - scalar
     - 0.0
     - 
     - Hockett–Sherby exponent H (n) — shape exponent on the plastic strain term controlling saturation speed (dimensionless; default 0.0).
   * - Last Strain
     - last_strain
     - scalar
     - 1.0
     - 
     - Maximum plastic strain value to which the extrapolated curve is extended (dimensionless; default 1.0; increase for very large-strain forming simulations).
   * - Increment
     - increment
     - scalar
     - 0.001
     - 
     - Strain step size used when evaluating the Hockett–Sherby formula across the extrapolation range (dimensionless; default 0.001; reduce for smoother high-resolution curves).

Outputs
-------

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

   * - Label
     - ID
     - Type
     - Description
   * - curve_effective_hocket_sherby_output_1
     - curve_effective_hocket_sherby_output_1
     - vector
     - Extrapolated effective stress–strain curve (vector of strain–stress pairs) generated by evaluating the Hockett–Sherby model from the end of the input curve up to last_strain, ready for direct use as a MAT_024 plasticity curve in LS-DYNA.

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_hocket_sherby <https://www.d3view.com/api/workflow/example?id=curve_effective_hocket_sherby>`_

.. raw:: html

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   <p style="font-size:11px;color:#888">
   Auto-generated from <code>transformation</code> schema. Worker id: <code>curve_effective_hocket_sherby</code>. Schema hash: <code>1c5738503ca5</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
   </p>