A3

B3

TR3

FIZ3

FMASS3

TR3R

XF3

XR3

YS3

54

Card:  Field

Variable

Description

Original

Units

Default

Units

Metric Units

54:1

A3

A₃

The distance from the center of gravity of V3 to the midpoint between the front wheels, taken as positive..

Inches

mm

54:2

B3

B₃

The distance from the center of gravity of V3 to the midpoint between rear wheels, taken as positive.

Inches

mm

54:3

TR3

T₃

Average tread width;  i.e., distance between the center of the  left and right tires, averaged over front and rear pairs.

(optional) Front tread width; i.e., distance between the center of the  left and right front tires if the Rear tread width is input in card 4 field 6 below.

Inches

mm

54:4

FIZ3

I_Z3

Yaw moment of inertia of V3. This is a measure of the torque needed to induce a rotation about a vertical axis through the center of gravity of V3 and it depends both on the total mass of the vehicle and on how far this mass is, on  average, from the center of gravity. For typical values of mass and of l (lz3=k xM), see the back page of this manual (from the CRASH3 Manual)

lb-sec²-in

kg-m²

54:5

FMASS3

M₃

The total mass of V3.  If vehicle weight in lbs is known, its mass  can be found by dividing by 386.4. (For DEFAULT option input is for weight)

lb-sec²/in

lbs.

kg

54:6

TR3-R

T_3R

(optional) Rear tread width; i.e., distance between the center of the  left and right rear tires. 

Note: This field in original SMAC was used for an optional rear axle steer angle; The inputs for vehicle 3 rear steer angle time history can optionally be input on m-smac input card(s) 60.

inches

mm

54:7

XF3

X_F3

Distance from center of gravity of V3 to the front end of the car body, taken as positive .

inches

mm

54:8

XR3

X_R3

Distance from center of gravity V3 to the rear end of the car body, taken as negative, may be entered as positive or negative.

inches

mm

54:9

YS3

Y_S3

Distance from the center of gravity of V3 to the side of the car body; 1/2 total width (this conforms with original SMAC).

YS3 may also be entered as the total vehicle width. The magnitude of YS3 is compared to the Track Width (TR3) and if YS3 > TR3, the input is assumed to be for the total width.

inches

mm