Vehicle Dynamics - a.y. 2016/2017
Period (Year/Semester): II/II
Required/expected prior knowledge: Nothing
Lecturers: Timpone Francesco
The aim of the course is to provide the fundamentals of road vehicles dynamics by using deductively developed physico-analytical models. The lecture investigates the handling of vehicle while cornering and maneuvering. The main problems related to tyre-road interaction, the longitudinal, lateral and vertical dynamics of the vehicle will be studied.
Tables of contents:
Tyre: Interaction with the road. Physical-analytical models. Normal interaction model of thetire approximated to an inextensible pressure shell. Simplified tangential interaction model: anisotropic brush model. Introduction to contact mechanics between elastic deformable bodies. Tyrekinematics: Pure Rolling; the concept of slip angle. The pseudo-sliding phenomenon: longitudinal and lateral sliding parameters; Spin parameter. Analytical determination of interaction forces and self-aligning moment in the presence of camber. Combined interactions. The adherence ellipse. The concept of longitudinal stiffness(braking stiffness) and lateral stiffness (cornering stiffness). Empirical models: Pacejka Magic Formula.
Vehicle: Aerodynamics. Longitudinal dynamics. Longitudinal load transfer. Braking: ideal and real brake balance. Lateral dynamics. kinematic and dynamic steering. Single track model. Lateral load transfer. Determination of axle characteristics. Dynamic equilibrium equations. Congruence equations. Tyre equations. Handling diagram. Handling and stability behavior of the vehicle in steady state conditions. Under steer generalized gradient. Typical maneuvers. Definition of over-under steer. Main suspension schemes. Behavior of the vehicle with suspension. Angles of yaw, pitch and roll. Equilibrium equations in curve. Vertical dynamics. Vibrational comfort for passengers. Road profiles. Vehicle models for vertical dynamics. Free and forced oscillations. Design criteria for stiffness and shock absorbers in suspensions.
Lessons and exercises.
Textbooks and learning aids:
M. Guiggiani – Dinamica del veicolo, Città Studi Edizioni, 2007
T.D. Gillespie - Fundamentals of Vehicle Dynamics, SAE, 1992
W.F. Milliken e D.L. Milliken - Race Car Vehicle Dynamics, SAE, 1995
J.C. Dixon - Tyres, Suspension and Handling, Cambridge University Press, 1991.
Assessment will be oral.