.. _auto_curve_get_linearity_yield:

*GET YIELD BASED ON END OF LINEARITY*
=====================================

Detects the yield point of a material by identifying the end of the linear (elastic) region on an engineering stress–strain curve. It fits a linear model over progressively larger strain windows and reports the yield strain at the point where the R² of the fit drops below the specified threshold. Use this worker when you need an objective, regression-based yield strain estimate from coupon test data.

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

Classification: **process**.

Tagged: ``curve_analysis``, ``elastic_region``, ``linearity``, ``material_characterization``, ``r2``, ``stress_strain``, ``yield``, ``yield_strain``.

Inputs
------

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

   * - Label
     - ID
     - Type
     - Default
     - Required
     - Description
   * - Eng Stress Vs Strain
     - curve
     - vector
     - —
     - 
     - Engineering stress vs. strain curve (X = strain, Y = stress) from which the yield point is extracted; typically output from a coupon test ingestion or curve-transform worker.
   * - Stop When X-strain Reaches This Value
     - xmax
     - scalar
     - 1
     - 
     - Upper strain limit (dimensionless) at which the linearity scan stops; defaults to 1.0 — reduce this value if the curve is short or plastic flow begins early.
   * - Min R2
     - min_r2
     - scalar
     - 0.975
     - 
     - Minimum acceptable R² coefficient (0–1) for the linear fit to be considered valid; the end of linearity is flagged when R² falls below this threshold — default 0.975 is appropriate for most metallic stress–strain curves.

Outputs
-------

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

   * - Label
     - ID
     - Type
     - Description
   * - Yield Strain
     - yield_strain
     - scalar
     - Dimensionless engineering strain value at the detected end of the linear (elastic) region, corresponding to the yield point of the material.

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

- data.curve.transform
- data.statistics
- 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_get_linearity_yield <https://www.d3view.com/api/workflow/example?id=curve_get_linearity_yield>`_

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   Auto-generated from <code>transformation</code> schema. Worker id: <code>curve_get_linearity_yield</code>. Schema hash: <code>40fe1177877b</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
   </p>