.. _auto_curve_generate_yield_curve:

*GENERATE YIELD CURVE*
======================

Generates a synthetic engineering stress–strain yield curve from key material parameters (modulus, yield stress, ultimate stress/strain, elongation) using either a linear or power-law scaling function between characteristic points. Use this worker to construct piecewise true stress–plastic strain curves for metal plasticity models (e.g., MAT_24) when only handbook or coupon-summary values are available.

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

Classification: **process**.

Tagged: ``MAT_24``, ``linear_interpolation``, ``material_curve_generation``, ``plastic_strain``, ``plasticity``, ``powerlaw``, ``stress_strain``, ``true_stress``.

Inputs
------

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

   * - Label
     - ID
     - Type
     - Default
     - Required
     - Description
   * - Modulus Of Elasticity
     - modulusof_elasticity
     - scalar
     - 210
     - 
     - Young's modulus of the material in GPa (default 210 GPa for steel); controls the elastic slope of the generated curve.
   * - Yield Stress
     - yield_stress
     - scalar
     - .150
     - 
     - Engineering yield stress in GPa (default 0.150 GPa = 150 MPa); defines the onset of plastic flow on the curve.
   * - Yield Point Elongation
     - yield_point_elongation
     - scalar
     - 0.0
     - 
     - Yield-point elongation (Lüders strain) in dimensionless strain units (default 0.0); set > 0 for materials exhibiting a flat yield plateau (e.g., mild steel).
   * - Ultimate Stress
     - ultimate_stress
     - scalar
     - .250
     - 
     - Engineering ultimate tensile stress in GPa (default 0.250 GPa = 250 MPa); defines the peak of the stress–strain curve before necking.
   * - Ultimate Strain
     - ultimate_strain
     - scalar
     - 0.3
     - 
     - Engineering strain at ultimate tensile stress, dimensionless (default 0.3); marks the end of the uniform-elongation region.
   * - Elongation Strain
     - elongation_strain
     - scalar
     - 0.4
     - 
     - Engineering strain at fracture / elongation-at-break, dimensionless (default 0.4); defines the terminal point of the generated curve.
   * - Yield Scaling Function
     - yield_scaling_function
     - scalar
     - linear
     - 
     - Interpolation function used between the yield point and the ultimate point — 'linear' (default) or 'powerlaw'; choose 'powerlaw' for Hollomon-type hardening in the post-yield region.
   * - Ultimate Scaling Function
     - ultimate_scaling_function
     - scalar
     - linear
     - 
     - Interpolation function used between the ultimate point and the fracture point — 'linear' (default) or 'powerlaw'; controls the shape of the post-necking segment of the curve.
   * - Yield Scaling Function Coeff
     - yield_scaling_function_coeff
     - scalar
     - 0.2
     - 
     - Exponent or coefficient for the yield-region scaling function (e.g., the Hollomon n-value for powerlaw); ignored when yield_scaling_function is 'linear'.
   * - Ultimate Scaling Function Coeff
     - ultimate_scaling_function_coeff
     - scalar
     - 2
     - 
     - Exponent or coefficient for the ultimate-to-fracture scaling function; ignored when ultimate_scaling_function is 'linear'.
   * - Number Of Points
     - numberof_points
     - scalar
     - 100
     - 
     - 

Outputs
-------

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

   * - Label
     - ID
     - Type
     - Description
   * - curve_generate_yield_curve_output_1
     - curve_generate_yield_curve_output_1
     - vector
     - Generated stress–strain yield curve as a two-column vector (strain, stress in input units) with np data points, ready for direct use in material card definitions such as MAT_24.

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

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

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

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

.. raw:: html

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   Auto-generated from <code>transformation</code> schema. Worker id: <code>curve_generate_yield_curve</code>. Schema hash: <code>b5ee9e019f68</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
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