/SENSOR/INTER

Block Format Keyword Describes the sensors used to activate or deactivate an object according to interface force.

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)	$[s]$
`int_ID`	Interface or sub-interface identification number. (Integer)
`DIR`	Force direction. = blank Activation at first force =FN Normal Force =FT Tangent Force (Integer)
`Fmin`	Minimum force. 3 Default = 0 (Real, maximum 20 fields)	$[N]$
`Fmax`	Maximum force. 3 Default = 0 (Real, maximum 20 fields)	$[N]$
`T`_min	Minimum time duration before activation when criteria is reached. (Real)	$[s]$
`F`_cut	Cutoff frequency. ≠ 0 A 4-pole Butterworth filter is used. (Real)	$[Hz]$

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 INTER:
A Sensor is activated when contact on interface is detected, and following force criteria is satisfied:
- $F_{c o n t} < F_{\min}$ or $F_{c o n t} > F_{\max}$ during T_min
Dir defines Force direction:

FN

Normal Force

TF

Tangent Force

Sensor is deactivated if the contact is lost

If there is no impact during a time equal to T_delay (Line 3), the sensor is deactivated.

A sensor is used for one interface or sub-interface. You can use several type INTER sensors.

Figure 1.
To obtain a class 1000 SAE filtering, the recommended value for F_cut is 1650 Hz (1.65 ms-1). Application of the filter helps to prevent wrong activation of the force-based sensor, due to a local force peak. Another method to avoid this is to use a small value for T_min.