Sensitivity Analysis for Estimation of Pavement Fatigue Life

Abstract

The fatigue life of pavements modeled as Winkler beams, with irregular profile, and traversed by vehicles modeled as nonlinear dynamic systems, is investigated in this article. Three computational methods are used to integrate the road equilibrium equation: the time domain superposition (Duhamel's integral), the frequency superposition based on a reference frame moving with the vehicle, and a very simple pseudodynamic scheme based on the static influence function in conjunction with the fluctuating loads. It will be shown that the frequency superposition method is significantly more efficient than time superposition, and that the simplified pseudodynamic method could be used as a reasonable first approximation. A vehicle model is used in conjunction with a profile model in order to obtain a sample force record with which to load the pavement. The response of the road is analyzed, and its fatigue life estimated, for different values of the parameters that describe the pavements. It will be shown that pavement thickness and modulus have a tremendous influence on fatigue life.