Fractional Plasticity Model for Coarse Aggregates Incorporating Particle Breakage under Triaxial Loading

Jiangong Yang,Yifei Sun,Yingchun Li

doi:10.1155/2021/6642461

Abstract

Fractional plasticity has been originally proposed for capturing the state-dependent nonassociated behaviour of sand, with no use of state variables and additional plastic potentials. However, for coarse aggregates, significant particle breakage would occur, which could influence the stress-strain behaviour of the material, by shifting the critical state line in the e − ln p ′ plane. In this note, an extension of the fractional plasticity for constitutive modelling of coarse aggregates is made by incorporating particle breakage under triaxial loading. The developed model is validated by simulating a series of laboratory test results of different coarse aggregates under triaxial loading, where a good agreement between the model simulations and test results is observed.

Highlights

IntroductionE.g., rockfill and ballast, have been widely used in constructing public facilities, due to its high mechanical qualities [1,2,3,4]
Coarse granular aggregates, e.g., rockfill and ballast, have been widely used in constructing public facilities, due to its high mechanical qualities [1,2,3,4]
It has been long found that when subjected to external loads, particle breakage would occur in coarse aggregates, which significantly influenced the strength and deformation behaviour of the material [5,6,7,8,9]

Summary

Introduction

E.g., rockfill and ballast, have been widely used in constructing public facilities, due to its high mechanical qualities [1,2,3,4]. Traditional constitutive approaches for soils were mainly based on linear critical state lines, which may not be suitable for coarse granular soils that exhibit high extent of particle breakage. To solve this problem, a series of elastoplastic models incorporating the concept of particle breakage have been proposed [12, 13]. A novel approach, the fractional plasticity [14,15,16,17], has been developed for modelling the state-dependent nonassociated behaviour for geomaterials, where no use of the additional plastic potentials was required This approach did not consider the effect of particle breakage on the constitutive behaviour of highly crushable soils. For more complex loading conditions, one can refer to Sun et al [15]

Fractional Plasticity considering Particle Breakage

Parameter Identification and Model Validation