.. _auto_dynakeyword_mat057:

*CREATE A MAT_057 FOR LS-DYNA*
==============================

Generates an LS-DYNA MAT_057 (*MAT_LOW_DENSITY_FOAM) keyword block from user-supplied material parameters and a nominal stress–strain compression curve. Use this worker whenever a low-density foam material card needs to be authored or updated programmatically inside a d3VIEW workflow.

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

Classification: **data**.

Tagged: ``deck_authoring``, ``foam``, ``keyword``, ``low_density_foam``, ``ls-dyna``, ``mat_057``, ``material_card``.

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 assigned to the MAT_057 card (e.g. 'LowDensityFoam_A'); appears in the LS-DYNA keyword header. Leave blank to omit a named header.
   * - Material ID
     - material_i_d
     - scalar
     - —
     - 
     - Integer material ID (MID) referenced by PART cards in the LS-DYNA deck; must be unique within the model. Leave blank to let the workflow assign an ID automatically.
   * - Curve Id
     - curve_id
     - scalar
     - —
     - 
     - Integer load-curve ID (LCID) pointing to the nominal stress vs. strain compression curve defined elsewhere in the deck; used when the curve is pre-existing rather than passed inline.
   * - Density
     - density
     - scalar
     - —
     - 
     - Mass density of the foam (RO) in consistent model units (e.g. kg/mm³ or t/mm³); required for mass-scaling and contact calculations.
   * - Elastic Modulus
     - elastic_modulus
     - scalar
     - —
     - 
     - Young's modulus (E) of the foam in consistent model units (e.g. MPa); governs the unloading stiffness in MAT_057.
   * - Hardening Curve
     - nominalstressvsstraincompressioncurve
     - vector
     - —
     - 
     - Inline nominal stress (y-axis, pressure units) vs. engineering strain (x-axis, dimensionless) compression curve passed as a two-column vector; used to populate the LCID field when no pre-existing curve ID is provided.
   * - Tensile Cut-off Stress
     - t_c
     - scalar
     - —
     - 
     - Tensile cut-off stress (TC) in consistent model units (e.g. MPa); elements erode or carry no tension beyond this threshold. Leave blank to use the LS-DYNA default (no tensile cut-off).
   * - HU
     - h_u
     - scalar
     - —
     - 
     - Hysteretic unloading factor (HU, dimensionless, 0–1) controlling energy dissipation during unloading; 1.0 = fully elastic unloading, values < 1 introduce hysteresis. Leave blank to use the LS-DYNA default.
   * - DAMP
     - dam_p
     - scalar
     - —
     - 
     - 
   * - SHAPE
     - shap_e
     - scalar
     - —
     - 
     - 
   * - KCON
     - kco_n
     - scalar
     - —
     - 
     - 
   * - Number Of Dig Points
     - numberof_dig_points
     - scalar
     - 200
     - 
     - LCINT

Outputs
-------

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

   * - Label
     - ID
     - Type
     - Description
   * - dynakeyword_mat057_output_1
     - dynakeyword_mat057_output_1
     - text
     - Plain-text LS-DYNA keyword block (*MAT_LOW_DENSITY_FOAM / MAT_057) ready to be included directly in a solver deck or passed to a downstream deck-assembly worker.

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

- cae.preprocessing.deck_authoring
- engineering.material.calibration
- 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_mat057</code>. Schema hash: <code>e3029f2c234e</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
   </p>