Define Preload, Offset and Scale

The Preload/Offset/Scale tab displays the force characteristics of your bushing as you see in the following figure:

Select the Preload/Offset/Scale tab.

Note: The Preload default value = 0; The Offset default value = 0; and the Scale default value = 1.0. The same holds true for both translational and rotational directions.
Enter the Preload Force X, Y and Z values as a real value. Positive preload (P_k) values act to attract the two bodies.
Enter the Preload Torque X, Y and Z values as a real value. Positive preload torque values act clockwise about the given axis (that is, x, y or z) on body 1 and counter-clockwise on body 2.
Enter the Offsets Disp X, Y and Z values as a real value. Displacement offsets (Q_k) are subtracted from the actual displacement of body 1 with respect to body 2.
Enter the Offsets Angle X, Y and Z values as a real value. Angle offsets are subtracted from the actual angular displacement.
Enter the Scales Disp X, Y and Z values as a positive, real value. The displacement scale (H_k) scales both the input displacement and velocity, but not the displacement offset. The default value is one (1).
Enter the Scales Angle X, Y an Z values as a positive, real value. The displacement scale (H_k) scales both the input displacement and velocity, but not the displacement offset. The default value is one (1).
Enter the Scales Force X, Y and Z values and Torque X, Y Z value as positive, real values. Enter a positive, real value. The force scale (V_k) scales the force function, but not the preload. The default value is one (1).

The following figure shows the effect of preload and offset on a bushing:

The bushing force for the K^th direction (x, y, z, ax, ay, az) is defined by a function:(1)

F_{k} = - G_{k} (q_{k}, {\dot{q}}_{k}, x_{k}, t)

Where,

$F_{k}$: Force in the k^th direction
$G_{k} (d_{k}, {\dot{d}}_{k}, x_{k}, t)$: Force function in the k^th direction
$d_{k}$: Displacement input in the k^th direction
${\dot{d}}_{k}$: Velocity input in the k^th direction
$x_{k}$: Array of internal state (that is, hysteresis) in the k^th direction
$t$: Time

The displacement offset Q_k and the displacement scale H_k modify the displacement and velocity to compute new inputs to function G as follows:

$q_{k} = H_{k} \cdot d_{k} - Q_{k}$ is the scaled, offset displacement.

${\dot{q}}_{k} = H_{k} \cdot d_{k}$ is the scaled velocity.

So force is then computed using the modified inputs

q_{k}

and

{\dot{q}}_{k}

:(2)

F_{k} = - G_{k} (q_{k}, {\dot{q}}_{k}, x_{k}, t)

Finally, the force/torque preload P_k and force/torque scale V_k modify the output so the force computation is:(3)

F_{k} = P_{k} - V_{k} \cdot G_{k} (q_{k}, {\dot{q}}_{k}, x_{k}, t)