Citation

Quinn BE, Thompson DR. Highw. Res. Board bull. 1962; 328: 24-32.

Copyright

(Copyright © 1962, National Research Council (U.S.A.), Highway Research Board)

DOI

unavailable

PMID

unavailable

Abstract

A vehicle traveling over a highway containing surface irregularities experiences vertical motion as well as horizontal motion. Associated with the vertical motion are forces between the highway and the vehicle that are developed in addition to the static weight of the vehicle. These forces are frequently referred to as the dynamic reactions or the dynamic forces. They depend on the vehicle suspension characteristics, the condition of the pavement, and the velocity of the vehicle. Laboratory tests were conducted to determine the frequencies of vibration at which passenger vehicles would develop large forces between the tires and the pavement. The relationship between force exerted by the tire and vertical displacement of the tire tread was measured at all frequencies at which any appreciable force was developed. The vehicle characteristic thus obtained included the actual effects of all components of the vehicle suspension system. A criterion of pavement condition was established by making power spectral density analyses of highway elevation measurements. A brief description of the physical significance of this criterion is included. A procedure is discussed for combining the vehicle characteristics with an elevation power spectrum (pavement condition criterion) at a selected vehicle velocity to obtain a dynamic force power spectrum. The usefulness of this result is discussed and curves of the root-mean squared value of the dynamic force vs vehicle velocity are included for three different pavement conditions. By using the criterion of pavement condition as defined in this paper, it is possible to estimate the dynamic force that one wheel of a vehicle will exert on a highway.