Example: Steer degree-of-freedom option inputs

 

The following example demonstrates the input format for the steer degree-of-freedom (SDOF) option. In this example, it is assumed that the impact, which occurs at 0.50 seconds, does not produce any steering system limiting damage and that neither driver applies any steering control.

 228.    600.    29.00   50000.  5.000   1.20                    0.5           25

 228.    600.    29.00   50000.  5.000   1.20                    0.5           26

 

An echo of the SDOF inputs used is as follows:

                S T E E R I N G   S Y S T E M

                                         VEHICLE#1          VEHICLE#2

          MOMENT OF INERTIA       XIPS  =   228.000        228.000 LB-SEC**2

          COULOMB FRICTION TORQUE CPSP  =   600.000        600.000 LB-IN

          FRICTION LAG            EPSP  =     5.000          5.000 DEG/SEC

          ANGULAR STOP RATE       AKPS  = 50000.000      50000.000 LB-IN/RAD

          ANGULAR STOP POSITION   OMGPS =    29.000         29.000 DEGREES

          PNEUMATIC TRAIL         XPS   =     1.200          1.200 INCHES

               STEER DEGREE-OF-FREEDOM OPTION CONTROL INPUTS:

          START TIME OF SDOF       TSDOF =    0.500          0.500 SEC

          INITIAL STEER ANGLE     PSIF  =      .000           .000 DEG

          INITIAL STEER VELOCITY  PSIFD =      .000           .000 DEG/SEC

          (NOTE:PSIF,PSIFD NOT USED IF TSDOF > 0.0 SEC)

 

The inputs for the steering system properties were derived from published measurements made for the HVOSM steer degree-of-freedom model by Griffith, et, all as part of a follow up study of the HVOSM curb impact option (see Ref. 15). The m-smac SDOF model is based on the HVOSM SDOF model.

Please note that the suggested values and ranges should be used as starting values. Some applications which use the SDOF may require values that are outside the suggested ranges.


More:

Barrier Option