unsprung weight

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unsprung weight

[¦ən′sprəŋ ′wāt]
(mechanical engineering)
The weight of the various parts of a vehicle that are not carried on the springs, such as wheels, axles, and brakes.
References in periodicals archive ?
A world first in this sector, these special rims save an extra 2kg per wheel in unsprung mass. Secured in tailored storage bags and stored in a special cradle behind the front seats, these wheels have been designed to unlock even greater on track potential.
Figure 2 shows the half-vehicle model, in which [z.sub.s](t) stands for the sprung mass heave motion, [z.sub.uf](t) for front unsprung mass vertical motion, [z.sub.rf](t) for rear unsprung mass vertical motion, and [theta] for pitching motion.
Various studies have been done to find out the parameters affecting the performance, and it was found that the rate of flow, orifice discharge coefficient, pressure drop across orifice, orifice dimensions, polytropic index, geometric parameters of chambers (length and diameter), internal gas pressure, hydraulic fluid properties, strut stroke length, unsprung mass, vertical forces acting on the shock strut, sliding friction, static seal friction, etc., play an important role in determining the shock strut performance [3, 4, 5, 6].
The carbon ceramic discs are also part of AMR's ethos to use lightweight components whilst reducing unsprung mass they have a noticeably beneficial effect on the driving experience.
Wheelend components carry additional benefit as unsprung mass, though the unsprung mass is most appreciated in performance cars where the entire system is optimized.
This function takes into account the axle load of vehicle body, unsprung mass, track irregularity, driving speed, load periodicity, movement and combination of loads, and the effect of rails and sleepers on the dispersion and transmission of loads, as shown in the following formula [30]:
Figures 17 and 18 mean that the vertical vibration of the body was reduced and the ride comfort improved, because the vertical motion of the unsprung mass and its impact on vehicle body were reduced.
Compared to a conventional brake system, the composite brake is characterised by its significantly lower weight which contributes to a reduction in unsprung mass.
The lightweight design of the wheels has three advantages: it reduces the overall weight, the rotatory mass and the unsprung mass.
Thus the objective of reducing the unsprung mass is achieved to a larger extent.
The unsprung mass [m.sub.u] represents the equivalent mass of the tire assembly system.