Dynamic Shakedown Analysis for Anisotropic Material Under Traffic Moving Loading

Abstract

Shakedown solution is widely used to analyze elastic-plastic behaviors of structures in pavement design. It is an effective way to predict the maximum admissible load (termed ‘shakedown limit’) against excessive rutting in flexible pavements. However, previous research is concerned with shakedown theorem under traffic loads without the influences of anisotropy. This paper has firstly proposed numerical analysis for anisotropic material under traffic moving load, based on Melan’s lower bound shakedown theory. An anisotropic Finite Element–Infinite Element (FE–IE) model with a user subroutine in ABAQUS is proposed to calculate the dynamic response of elastic stress against load moving speeds. Shakedown limits for an anisotropic half-space pavement system under traffic moving loads at various speeds are investigated. It is found that the shakedown limit decreases when the load moving speed increases towards the Rayleigh wave speed of the pavement for isotropic half-space system. For cross-anisotropic half-space system, Poisson’s ratio only leads to negligible effect on shakedown limit. Furthermore, the shakedown limit rises with the increasing cohesion ratio c v /c h , but it reaches maximum value when cohesion ratio is larger than a specific value. And the maximum shakedown limit rises slightly with the increase of moving speed below Rayleigh wave speed.