Knowledge of the functional and dynamic aspects characterizing cars, trucks, motorcycles. Forces. Performances in straight line motions. Curvilinear motions. Directional behavior. Handling and comfort. Motivations of design choices. The goal is to provide the fundamental elements for understanding, evaluating, and modeling the phenomena and for tuning the vehicle, based on the knowledge of the effects of the parameters which may be modified
Lectures
Forces exchanged between vehicle and road. Definitions and reference frames. Pressures of contact and stiffness of the tire. Radius of rolling. Rolling resistance. Forces exchanged between wheel and road in longitudinal direction. Forces exchanged between wheel and road in transverse direction. Interaction between longitudinal and transverse forces. Elements on the dynamic behavior of tire. Experimental measurement of the tire characteristics. Tires and wheel rims and their designation. Aerodynamic actions. Expressions of the aerodynamic forces and moments. Evaluation of the car performances in straight line motion. Power necessary for constant speed motion. Maximum power transmissible at the contact between wheel and road. Performances of internal combustion engine vehicles. Energy consumption of cars. Breaking on straight line roads. Toe in, toe out, camber, caster, scrub radium (offset), caster trail. Curvilinear motion of vehicle. Kinematic steering of vehicles and of trailers. Steady state motion. Three degree of freedom linearized model for two axes vehicles. Two axes vehicles integral steering. Effect of suspensions on the behavior of the vehicle. Car suspensions. Roll and pitch centers. Anti-dive and anti-squat. Shock absorbers and their details of design and of tuning. Tuning of competition vehicles. Transmissions. Gearboxes. Differentials, viscous joint. Vehicles having one or two driving axes. Dynamics of vehicle and road accidents. Impact between vehicles: centered impact, oblique, against a fixed obstacle. Response of a vehicle to irregularities of the ground, characterized as random variables. Capsize, weave, and wobble motions of motorcycles. Gyroscopic effects on motorcycles. Execution of curves at low and at high speed with motorbikes. Effect of chain force on motorcycles. Effect of tires on motorcycles. Motorcycles and scooters suspensions. Setup of racing motorbikes. Telemetry. Comparison between the characteristics and the performances of cars and of motorcycles.
- Didactic material provided by the teacher
- Giancarlo Genta “Meccanica dell’autoveicolo”, Levrotto e Bella, Torino, 2000
- Vittore Cossalter “Motorcycle dynamics”, Race Dynamics, 8421 Midland Dr.,Greendale, WI 53129, USA, 2002
ALERAMO LUCIFREDI (President)
MATTEO ZOPPI (President Substitute)
Oral examination. Examination date fixed through agreement with the teacher.
