Some fundamental definitions of the elastic parameters for homogenous isotropic linear materials in road design and analysis

Abstract

This paper is a brief introduction to some of the well known fundamental engineering properties of homogeneous isotropic linear elastic materials. It specifically shows the relationships between different elastic moduli. It covers some of the extensive (but not so well known) relationships between the various moduli of these materials and also illustrates the importance of parameters such as Poisson’s Ratio. The aim of the paper is to summarise the fundamental elastic properties of the above types of materials, as well as their interrelationships and to use these as background to engineering in road modelling and simulation. An additional aim is to show that moduli measured under different conditions should probably be treated differently, such as creep speed measurements of elastic surface deflection basins carried out with the Benkelman Beam (BB) (or Road Surface Deflectometer (RSD)) associated with Heavy Vehicle Simulator (HVS) testing, and those measured under relatively short time impulse loading (i.e. seismic) by means of the Falling Weight Deflectometer (FWD)