.. _auto_dynakeyword_mat123:

*CREATE A MAT_123*
==================

Generates an LS-DYNA MAT_123 (*MAT_MODIFIED_PIECEWISE_LINEAR_PLASTICITY) keyword block from user-supplied material parameters. Use this worker to programmatically author or inject a MAT_123 card into a simulation deck without hand-editing keyword files.

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

Classification: **data**.

Tagged: ``deck_authoring``, ``keyword``, ``ls-dyna``, ``mat_123``, ``mat_modified_piecewise_linear_plasticity``, ``material_card``, ``plasticity``.

Inputs
------

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

   * - Label
     - ID
     - Type
     - Default
     - Required
     - Description
   * - Material Name
     - material_name
     - scalar
     - —
     - 
     - Alphanumeric label written into the MAT_123 card header (e.g. 'Steel_DP600'); optional — leave blank to omit the name field.
   * - Material ID
     - material_i_d
     - scalar
     - —
     - 
     - Integer material ID (MID) used in the LS-DYNA deck to reference this card; optional — leave blank to let downstream workers assign the ID.
   * - Starting Table ID
     - starting_table_i_d
     - scalar
     - —
     - 
     - Integer ID for the first TABLE entry generated alongside the material card (e.g. strain-rate table); optional — omit if no tables are required.
   * - Starting Curve Id
     - starting_curve_id
     - scalar
     - —
     - 
     - Integer ID for the first DEFINE_CURVE entry generated alongside the material card (e.g. effective-stress vs. effective-plastic-strain); optional — omit if no load curves are required.
   * - Density
     - density
     - scalar
     - —
     - 
     - Mass density (RO) of the material in model units (e.g. kg/mm³ or t/mm³); required for a valid MAT_123 card.
   * - Elastic Modulus
     - elastic_modulus
     - scalar
     - —
     - 
     - Young's modulus (E) in model pressure units (e.g. MPa or GPa); required for elastic response.
   * - Poissons Ratio
     - poissons_ratio
     - scalar
     - —
     - 
     - Poisson's ratio (PR), dimensionless, typically 0.28–0.33 for metals; required for elastic response.
   * - SIGY
     - sig_y
     - scalar
     - —
     - 
     - Initial yield stress (SIGY) in model pressure units (e.g. MPa); sets the onset of plastic flow — required when no load curve is supplied.
   * - ETAN
     - eta_n
     - scalar
     - —
     - 
     - Tangent modulus (ETAN) in model pressure units used for bilinear hardening; optional — leave blank when a piecewise-linear hardening curve is provided instead.
   * - FAIL
     - fai_l
     - scalar
     - —
     - 
     - 
   * - C
     - c
     - scalar
     - —
     - 
     - 
   * - P
     - p
     - scalar
     - —
     - 
     - 
   * - LCSS
     - lcs_s
     - vector
     - —
     - 
     - LCSS   <a class='btn btn-xs btn-default' target='_blank' href='https://www.d3view.com/docs/master/workflows/Glossary.html#curveinput'> <i class='fa fa-external-link'> </i> View more </a>
   * - LCSR
     - lcs_r
     - vector
     - —
     - 
     - LCSR   <a class='btn btn-xs btn-default' target='_blank' href='https://www.d3view.com/docs/master/workflows/Glossary.html#curveinput'> <i class='fa fa-external-link'> </i> View more </a>
   * - Strain Rates
     - strain_rates
     - scalar
     - —
     - 
     - 
   * - EPSTHIN
     - epsthi_n
     - scalar
     - —
     - 
     - 
   * - EPSMAJ
     - epsma_j
     - scalar
     - —
     - 
     - 
   * - NUMINT
     - numin_t
     - scalar
     - —
     - 
     - 
   * - Viscoplasticity
     - viscoplasticity
     - string
     - 0.0
     - 
     - 
   * - Number Of Dig Points
     - numberof_dig_points
     - scalar
     - 200
     - 
     - Number of Dig Points

Outputs
-------

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

   * - Label
     - ID
     - Type
     - Description
   * - dynakeyword_mat123_output_1
     - dynakeyword_mat123_output_1
     - text
     - Plain-text LS-DYNA keyword block containing the fully formed *MAT_MODIFIED_PIECEWISE_LINEAR_PLASTICITY (MAT_123) card, ready to be appended to or included in a simulation input deck.

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

- cae.preprocessing.deck_authoring
- engineering.material.characterization
- engineering.material.library

.. raw:: html

   <hr style="margin-top:2em">
   <p style="font-size:11px;color:#888">
   Auto-generated from <code>transformation</code> schema. Worker id: <code>dynakeyword_mat123</code>. Schema hash: <code>a03d8605f39a</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
   </p>