Contact Friction Force Calculation
Adams Solver uses a relatively simple velocity-based friction model for contacts. Specifying the frictional behavior is optional. The figure below shows how the coefficient of friction varies with slip velocity.
Coefficient of Friction Varying with Slip Velocity
In this simple model:
■
(-vs) =
s
(-vs) =s ■
(vs) = -
s
(vs) = -s ■
(0) = 0
(0) = 0 ■
(-vd) =
d
(-vd) =d ■
(vd) = -
d
(vd) = -d ■
(v) = -sign(v). 
dfor |v| >vd
(v) = -sign(v). dfor |v| >vd ■
(v) = -step(|v|,vs,
s, vd, 
d) sign(v) for vs < |v| < vd
(v) = -step(|v|,vs,s, vd, d) sign(v) for vs < |v| < vd■
(v) = step(v,-vs,
s,vs,-
s) for -vs < v < vs
(v) = step(v,-vs,s,vs,-s) for -vs < v < vs where:
■V: Slip velocity at contact point
■vs: STICTION_TRANSITION_VELOCITY
■vd: FRICTION_TRANSITION_VELOCITY
■
s: MU_STATIC
s: MU_STATIC■
d: MU_DYNAMIC
d: MU_DYNAMIC