/SENSOR/HIC

Block Format Keyword Describes the sensors used to activate or deactivate an object according to Head Injury Criteria (HIC).

Format

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)
`T`_delay	Time delay. (Real)	$[s]$
`accel_ID`	Accelerometer identifier. (Integer)
`gauge_ID`	Gauge identifier. (Integer)
`DIR`	Force direction. =R (Default) Resultant =X X direction =Y Y direction =Z Z direction (Integer)
`Period`	Time window for the HIC. Default = 0.036, $[s]$ if in SI unit (Real)	$[s]$
`Value`	HIC limit value. Default = 1E20 (Real)	$[s]$
`Gravity`	Time window for the HIC. Default = 9.80665 $[\frac{m}{s^{2}}]$ if in SI unit (Real)	$[\frac{m}{s^{2}}]$
`T`_min	Minimum time duration before activation when criteria is reached. 3 (Real)	$[s]$

Sensors can be used to activate airbags, imposed forces, pressures, and fixed velocities.
Sensors can be used to activate or deactivate these elements: brick, quad, shell, truss, beam, spring or 3N Shell with /ACTIV.
For Sensor type HIC, criteria is computed with:(1)
$H I C_{P e r i o d} = \max {(t_{2} - t_{1}) {[\frac{1}{t_{2} - t_{1}} \int_{t_{1}}^{t_{2}} a (t) . d t]}^{\frac{5}{2}}}$

With $(t_{2} - t_{1}) < P e r i o d$ and $a (t) = \frac{a c c e l e r a t i o n (t)}{g r a v i t y}$ .

The sensor is activated when $H I C_{P e r i o d} > v a l u e$ after T_min value.