Laplace distribution models for road topography and roughness
Keywords:
Road profile, topography, road roughness, generalized Laplace distribution, non-Gaussian process, autoregressive process, power spectral density, (PSD), ISO spectrum, international roughness index (IRI), vehicle durability, fatigue damage.Abstract
Gaussian models are frequently used for road profiles. However, these models are often only valid for short sections of the road. Here we present a comprehensive approach to describe various aspects of road surface/elevation by using extensions of Gaussian models arising from random gamma distributed variances. These random variances result in the Laplace distribution and thus we refer to the so defined models as Laplace models. The approach is shown to perform well in modelling road topography, road roughness and multi-valued responses of forces and bending moments containing transients. The different Laplace models are presented together with numerical examples and Matlab code for simulation.
