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


(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
int_ID DIR Fmin Fmax Tmin Fcut


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.


[ s ]
int_ID Interface or sub-interface identification number.


DIR Force direction.
= blank
Activation at first force
Normal Force
Tangent Force


Fmin Minimum force. 3

Default = 0 (Real, maximum 20 fields)

[ N ]
Fmax Maximum force. 3

Default = 0 (Real, maximum 20 fields)

[ N ]
Tmin Minimum time duration before activation when criteria is reached.


[ s ]
Fcut Cutoff frequency.
A 4-pole Butterworth filter is used.




  1. Sensors can be used to activate airbags, imposed forces, pressures, and fixed velocities.
  2. Sensors can be used to activate or deactivate these elements: brick, quad, shell, truss, beam, spring or 3N Shell with /ACTIV.
  3. 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 Tmin
    Dir defines Force direction:
    Normal Force
    Tangent Force

    Sensor is deactivated if the contact is lost

    If there is no impact during a time equal to Tdelay (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.
  4. To obtain a class 1000 SAE filtering, the recommended value for Fcut 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 Tmin.