“Experimental validation of a driveline numerical model for the study of vibrational comfort of a vehicle”

ABSTRACT In this paper numerical models for the simulation and the experimental evaluation of the driveline from a vehicle with internal combustion, have been developed. In order to evaluate the dynamic coupling between engine and vehicle by the driveline, a code that implements a model with concentrated parameters of the driveline (engine, transmission, clutch, differential, axle shaft and wheels) has been applied. The code is able to measure the torque response, from 6 to 200 Hz. This aspect is particularly important as it has a significant impact on the vibrational comfort of a vehicle. A comparison was performed between the calculation results and the experimental ones relative to the simulation of an acceleration maneuver of the Fiat Punto 75. The comparison between the calculation and experimental data has provided encouraging results and indications to continue during the future activity. INTRODUCTION The simulation codes of internal combustion engine (gasoline or diesel) working, represent an important support tool during the design activity and for the capacity to foresee specific consumption and the performances of the vehicle. These codes had a strong development, contemporary with the progress of computer techniques, that are economic in comparison with the prototype experimentation. The use of simulation codes needs on the other hand an efficient test validation that confirms its accuracy and reliability. This paper describes the development of a dynamic simulation model of the driveline and the successive experimental activity performed for the validation. This model has been implemented with a numerical code which allows to get information on the vibrational modes and the relative deformed shape of the driveline, and on those phenomena that control the car's vibro-acoustic comfort. Therefore this code allows to reproduce the response of the driveline to the exciting torque generated by the engine, and the phenomena connected to the torsional vibrations along the driveline. The model has then been experimentally validated by a significant application.