.. _auto_curve_split_join_effective:

*SPLIT OR JOIN HARDENING/EFFECTIVE CURVE AT THE NECKING POINT*
==============================================================

Splits an effective stress–strain curve at the necking point into pre- and post-neck segments, or joins a pre-neck effective curve with a separately provided post-neck curve. Use this worker during material characterisation workflows to isolate or recombine the hardening and post-necking regions of a true stress–strain relationship.

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

Classification: **process**.

Tagged: ``curve_split``, ``effective_curve``, ``hardening``, ``join``, ``material_characterization``, ``necking``, ``post_neck``, ``split``.

Inputs
------

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

   * - Label
     - ID
     - Type
     - Default
     - Required
     - Description
   * - Effective Stress vs Strain Curve
     - effective_stressvs_strain_curve
     - vector
     - —
     - 
     - Effective (true) stress vs. plastic strain curve to be split at the necking point or used as the pre-neck segment in a join operation; expected as a two-column (strain, stress) vector.
   * - Modulus
     - modulus
     - float
     - 210.0
     - 
     - Material Young's modulus in GPa (default 210.0 for steel) used to locate the elastic–plastic transition and correctly identify the necking onset point.
   * - Split or Join
     - type
     - scalar
     - split
     - 
     - Operation mode: 'split' (default) detaches the curve at the necking point and returns the post-neck segment; 'join' concatenates the pre-neck curve with the curve supplied via post_neck_curve.
   * - Offset the post-neck curve so the first point is at x=0
     - offset
     - scalar
     - yes
     - 
     - When 'yes' (default), the post-neck curve is zero-offset so its first strain point starts at x=0; set to 'no' to preserve the original strain axis of the post-neck segment.
   * - Post-neck curve to be joined
     - post_neck_curve
     - vector
     - yes
     - 
     - Post-necking stress–strain curve to be appended in join mode; ignored when type='split'. Provide as a two-column (strain, stress) vector or CurveGroup (first curve is used).

Outputs
-------

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

   * - Label
     - ID
     - Type
     - Description
   * - Output Curve
     - curve_output
     - vector
     - Resulting stress–strain curve: in split mode, the isolated post-neck segment; in join mode, the full pre-neck + post-neck concatenated curve, optionally zero-offset.

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

.. raw:: html

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   Auto-generated from <code>transformation</code> schema. Worker id: <code>curve_split_join_effective</code>. Schema hash: <code>9927bc420081</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
   </p>