
145
Magnetorheological (MR) Suspension System for Tracked Vehicles
where H
mr
is the applied magnetic eld whose unit is A/mm. The magnetic
eld is related by /2H NI t
mr d
= . N is the coil turns of the MR valve and I is the
current. The coefcient C is intrinsic value of the MR uid to be experimentally
determined. The pressure in the accumulator can be calculated as follows:
0
0
0
P P
V
V A x
a
s p
=
+
γ
(5.41)
where P
0
and V
0
are initial pressure and volume of the accumulator. γ is the
coefcient of thermal expansion, which ranges from 1.4 to 1.7 for adiabatic
expansion. δ
p
is the piston displacement. It is noted that the piston displace-
ment