The effect of wheel unbalance on vehicle dynamics

Citation

Srinivasan, Prabandam (1956) The effect of wheel unbalance on vehicle dynamics. Engineer's thesis, California Institute of Technology. doi:10.7907/KDJ4-3T33. https://resolver.caltech.edu/CaltechETD:etd-06292004-164006

Abstract

Some unbalance either inherent or induced is always to be expected in automobile wheels. It may be inherent due to imperfect balancing of the wheel or it may be induced by the uneven wear of the tires. While in motion this unbalance simultaneously sets up two vibrations in the wheel, one a linear vibration normal to the road and the other an angular vibration about the king pin. The frequency of these vibrations depends on the forward speed of the vehicle and when it coincides with the natural frequency of vibration of the wheels the well known phenomenon of resonance occurs. The research reported in this thesis is a systematic investigation of this phenomenon in one front wheel of an automobile with the other three wheels in true balance. Known amounts of unbalance (both static and dynamic) were introduced into the left front wheel and road tests were conducted over a range of speeds covering resonance. Vibration pickups on the wheels recorded both vertical and angular displacement as a function of speed. Response curves have been plotted with the amount and type of unbalance as parameters. Also an attempt has been made to establish some bounds for the amount of unbalance that are noticeable to the passengers while traveling through the range of resonance.

Thesis Files