Be the first to like this
The mass properties of a vehicle affect its motion in all directions, translational and rotational. Previously this author has dealt with how mass properties affect automotive longitudinal acceleration and automotive lateral acceleration . Now a consideration is in order of how mass properties affect automotive vertical acceleration. Of course, lateral or longitudinal inputs can lead to vertical responses; every aspect of a vehicle’s dynamics is interconnected with every other aspect, but it is convenient to divide up automotive dynamics as if the subject were truly a matter of independent motions in the longitudinal, lateral, and vertical directions.
Initially, this paper will investigate the significance of mass properties with regard to automotive ride (transmission of road shock & vibration) and road-holding (maintaining contact at the tire/road interface) through the use of simple, undamped, 1-DOF models. Later, the full story of how mass properties influence the bounce and pitch motions of the sprung mass will necessitate recourse to more complex 2-DOF models. The mass properties of greatest relevance to this investigation will prove to be the “sprung mass”, the “unsprung masses”, the “sprung mass distribution” (longitudinal, lateral, and vertical c.g.), the rotational inertias of the rotating portions of the “unsprung masses”, and the “sprung mass” longitudinal and lateral mass moments of inertia.