.. _auto_dynakeyword_mat077_ogden_rubber:

*CREATE A MAT_OGDEN RUBBER*
===========================

Generates an LS-DYNA MAT_077 (Ogden rubber) keyword block for hyperelastic rubber material modeling. Accepts Ogden model parameters — density, Poisson's ratio, order of fit, optional Prony series for viscoelasticity, and frequency-damping controls — and emits a fully formed *MAT_OGDEN_RUBBER keyword string ready for deck inclusion.

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

Classification: **data**.

Tagged: ``deck_authoring``, ``hyperelastic``, ``keyword``, ``ls-dyna``, ``mat_077``, ``mat_ogden_rubber``, ``ogden``, ``prony``.

Inputs
------

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

   * - Label
     - ID
     - Type
     - Default
     - Required
     - Description
   * - Material Name
     - material_name
     - scalar
     - MAT_077
     - ✓
     - User-defined label for the material card (string, e.g. 'RUBBER_FOAM'); defaults to 'MAT_077' if left unchanged.
   * - Material ID
     - material_i_d
     - scalar
     - 1
     - ✓
     - Integer LS-DYNA material ID (MID) that uniquely identifies this card in the deck; defaults to 1.
   * - Density
     - rh_o
     - scalar
     - 1.5e-09
     - ✓
     - Mass density (RHO) in consistent units — default 1.5e-9 tonne/mm³ for typical rubber in an mm/ms/N system.
   * - Poissons Ratio
     - p_r
     - scalar
     - 0.45
     - ✓
     - Poisson's ratio (PR) for the rubber; 0.45 is the default, reflecting near-incompressibility typical of elastomers.
   * - Order Of Fit
     - n
     - scalar
     - 1
     - ✓
     - Order of the Ogden strain-energy fit (N); controls how many µ/α pairs are used — 1 (default) to 3 are typical for rubber.
   * - NV
     - n_v
     - scalar
     - 1
     - 
     - Number of Prony series terms (NV) used for viscoelastic relaxation; set to 0 to suppress viscoelasticity, default is 1.
   * - Shear Relaxation Modulus
     - g
     - scalar
     - 1
     - 
     - Long-term shear relaxation modulus G (stress units consistent with RHO); provides the elastic baseline for the Prony series, default 1.
   * - SIGF
     - sig_f
     - scalar
     - —
     - 
     - Limit stress SIGF for frequency-independent frictional damping (stress units); leave null/blank to disable this damping contribution.
   * - REF
     - re_f
     - scalar
     - 0
     - 
     - Use reference geometry to initialize the stress tensor
   * - SGL
     - sg_l
     - scalar
     - 1
     - 
     - 
   * - SW
     - s_w
     - scalar
     - 1
     - 
     - 
   * - ST
     - s_t
     - scalar
     - 1
     - 
     - 
   * - Curve Id
     - curve_id1
     - scalar
     - —
     - ✓
     - 
   * - LCID1
     - lci_d1
     - vector
     - —
     - ✓
     - 
   * - DATA
     - dat_a
     - scalar
     - —
     - 
     - 
   * - Curve Id
     - curve_id2
     - scalar
     - —
     - 
     - Curve Id 2
   * - LCID2
     - lci_d2
     - vector
     - —
     - 
     - 
   * - BSTART
     - bstar_t
     - scalar
     - —
     - 
     - 
   * - TRAMP
     - tram_p
     - scalar
     - —
     - 
     - 

Outputs
-------

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

   * - Label
     - ID
     - Type
     - Description
   * - dynakeyword_mat077_ogden_rubber_output_1
     - dynakeyword_mat077_ogden_rubber_output_1
     - text
     - Fully formatted *MAT_OGDEN_RUBBER (MAT_077) LS-DYNA keyword text block, ready to be written into or appended to an input deck.

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

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

.. raw:: html

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   <p style="font-size:11px;color:#888">
   Auto-generated from <code>transformation</code> schema. Worker id: <code>dynakeyword_mat077_ogden_rubber</code>. Schema hash: <code>abbf6211763f</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
   </p>