.. _auto_injury_nij:

*COMPUTE THE NIJ BASED ON THE OCCUPANT NECK AXIAL, SHEAR AND MOMENT TIME-HISTORY*
=================================================================================

Computes the Nij neck injury criterion (and its sub-components Nte, Ntf, Nce, Ncf) from occupant neck axial force, shear force, and bending moment time histories. Use this worker when evaluating neck injury risk in frontal or rear crash simulations against FMVSS 208 / NCAP thresholds for Hybrid III 5th-percentile or 50th-percentile dummies.

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

Classification: **process**.

Tagged: ``"``, ``0``, ``2``, ``8``, ``_``, ``a``, ``b``, ``c``.

Inputs
------

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

   * - Label
     - ID
     - Type
     - Default
     - Required
     - Description
   * - Axial Force time history
     - axial_forcetimehistory
     - vector
     - —
     - 
     - Neck axial force time history (N vs. s); positive values indicate tension, negative indicate compression — typically extracted from the Hybrid III upper neck load cell.
   * - Shear force time history
     - shearforcetimehistory
     - vector
     - —
     - 
     - Neck shear force time history (N vs. s) from the upper neck load cell; used in combination with axial force and moment to compute Nij components.
   * - Moment time history
     - momenttimehistory
     - vector
     - —
     - 
     - Neck bending moment time history (N·m vs. s) from the upper neck load cell; positive values indicate flexion, negative indicate extension.
   * - injurytype
     - injurytype
     - string
     - nte
     - 
     - Selects which Nij component to return: 'nte' (tension–extension), 'ntf' (tension–flexion), 'nce' (compression–extension), 'ncf' (compression–flexion), or 'nij' (overall peak); defaults to 'nte'.
   * - Occupant Type
     - occupant_type
     - string
     - H3-5
     - 
     - Hybrid III dummy size used to select the normalisation intercept values (Fint, Mint) per FMVSS 208: 'H3-5' for 5th-percentile female, 'H3-50' for 50th-percentile male; defaults to 'H3-5'.

Outputs
-------

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

   * - Label
     - ID
     - Type
     - Description
   * - injury_nij_output_1
     - injury_nij_output_1
     - vector
     - Time history of the selected Nij component (dimensionless) as a vector; the peak value of this curve is the reportable injury criterion against the regulatory limit of 1.0.

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

- engineering.crash.occupant_safety

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   Auto-generated from <code>transformation</code> schema. Worker id: <code>injury_nij</code>. Schema hash: <code>feba1950230a</code>. Hand-curated docs in <code>workerexamples/</code> override this page when present.
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