Impact of Suspension Failures on the Dynamic Response of a Vehicle Multibody Model
Palavras-chave:
Vibrational mechanics, Vehicle system dynamics, Vehicle comfort, Exposure to vibrationsResumo
Irregularities in road profiles generate excitations in the tires of vehicles traveling
over them. These excitations are absorbed by the vehicle's suspension, which has the function
of minimizing the transfer of these forces to the vehicle’s body, and consequently to the driver
and passengers, ensuring both comfort and safety for the individuals, as well as protection for
the vehicle’s cargo. This study aims to analyze the dynamic behavior of a vehicle traveling on
an irregular road profile to evaluate how a failure in the vehicle’s suspension influences
comfort, vehicle safety, and the driver’s health. Initially, a class C road, considered a reference
for Brazilian roads according to the ISO 8608:2016 standard, was modeled during a predefined
time and speed. Using a seven-degrees-of-freedom multibody model of a full vehicle, plus one
degree of freedom for the driver’s seat, a calculation routine was developed using Python
programming language for the numerical integration of the dynamic interaction between the
vehicle and the road. Vibration modes of the vehicle’s sprung mass and its wheels were obtained
for verification with literature results, as well as displacements and accelerations of the various
degrees of freedom to assess the Power Spectral Density - PSD associated to comfort and
handling parameters of the vehicle. Finally, using the ISO 2631-1:2010 standard, the health
guidance zones for a predefined expected daily exposure of the driver were determined. After
verifying the calculation routine, several faults were implemented: for instance, one in the right
front damper and another simulating irregular tire inflation on the same wheel, in order to
evaluate the sensitivity of the vehicle's dynamic behavior and how such failures impact the
driver’s health, emphasizing the importance of vehicle maintenance. The results obtained can
be extrapolated to other road profiles and speeds, as well as include defects in the driver's
suspension.
