/SENSOR/NIC_NIJ
Block Format Keyword Describes the sensors based on Neck Injury Criteria (NIC), which are used to activate or deactivate an object according to the defined characteristics.
This sensor is based on the Neck Injury Criterion Nij, developed by the National Highway Traffic Safety Administration (NHTSA). It uses forces and moments computed in the spring to which it is attached. Tension or compression axial force are combined with flexion or extension bending moment and compared to a given critical value (Nij_max).
Format
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
/SENSOR/NIC_NIJ/sens_ID/unit_ID | |||||||||
sens_title | |||||||||
Tdelay | |||||||||
Nij_max | Fint_tension | Fint_compression | Mint_flexion | Mint_extension | |||||
Spring_ID | Skew_ID | Axial_dir | Bend_dir | ||||||
Tmin | α | CFC |
Definition
Field | Contents | SI Unit Example |
---|---|---|
sens_ID | Sensor identifier. (Integer, maximum 10 digits) |
|
unit_ID | (Optional) Unit Identifier. (Integer, maximum 10 digits) |
|
sens_title | Sensor title. (Character, maximum 100 characters) |
|
Tdelay | Time delay. Default = 0.0 (Real) |
|
Nij_max | Nij limit value. Default = 1.0 (Real) |
|
Fint_tension | Critical axial force in
tension. Default = 6806.0 N (Real) |
|
Fint_compression | Critical axial force in
compression. Default = 6160.0 N (Real) |
|
Mint_flexion | Critical bending moment in
flexion. Default = 310.0 N.m (Real) |
|
Mint_extension | Critical bending moment in
flexion. Default = 135.0 N.m (Real) |
|
Spring_ID | Spring element identifier. 2 (Integer) |
|
Skew_ID | Skew system identifier. 3 Default = Skew system attached to the property of the spring (Integer) |
|
Axial_dir | Direction for axial force
monitoring. 4 Default = Z (Text) |
|
Bend_dir | Direction for bending moment
monitoring. 4 Default = Y (Text) |
|
Tmin | Minimum time duration before
activation when criteria is reached. Default = 0.0 (Real) |
|
α | Filter constant. 5 Default = 2.0775 (Real) |
|
CFC | Filter Channel Frequency Class.
5 Default = 600 (Real) |
Comments
- Neck Injury criterion
Nij is computed with:
(1) Where,- Corresponding axial force.
- Corresponding bending moment.
- Identifier of the spring from which the force and moment will be computed (select the spring corresponding to the upper neck load cell of the Dummy).
- Dummy’s spring modeling to the upper neck load cell is supposed to be a TYPE8 spring with a local skew system attached (in the property); this skew is supposed to be orientated according to standardized orientation.
- If the spring referred to in the sensor is oriented according to standardized orientation, Axial_dir and Bend_dir do not need to be defined.
- force and moment used in Equation 1 are filtered according to SAE J211-1, using CFC-600 filter. CFC and α can be adjusted for other CFC filters. Since forward-backward filter is calculated in runtime, its output is delayed by several cycles.
- Standardized
orientation (SAE J211-1):
- Positive X-axis is directed from the posterior to the anterior of the dummy
- Positive Y-axis is directed from the dummy’s left to the dummy’s right
- Positive Z-axis is directed from superior to interior
- This sensor can be used to terminate a simulation at specific conditions with the Engine keyword /STOP/LSENSOR.