Study on elastoplastic coupling mechanics model of the milled mixture of sugar cane

Qingshan Duan,Hanling Mao,Hanying Mao,Bing Li,Zhenfeng Huang,Xinxin Li

doi:10.1590/fst.02518

Abstract

Abstract At present, the phenomenon of elastoplastic coupling isn’t considered in establishing the mechanics model of the milled mixture of sugar cane. In order to describe elastoplastic coupling and yield characteristics, based on uniaxial confined compression tests and direct shear tests, the evolution of the elastic parameters of the solid fiber with void ratio and the plastic deformation, and the plastic mechanics behavior of the solid fiber is described by Modified Drucker-Prager Cap model, the expressions of the parameters of the plastic mechanics model are derived and the corresponding parameters are calculated; and the elastoplastic coupling mechanics model is established. The evolution of the parameters of the model is achieved by the custom subroutine written in Fortran, the numerical simulation of the elastoplastic coupling model is realized by ABAQUS. The results of uniaxial confined compression tests and finite element simulation show that the elastoplastic coupling mechanics model is more accurate than the non-elastoplastic coupling mechanics model to predict the axial pressure. The results provide an important reference for the analysis and understanding of the milling process of sugar cane and the establishment of an accurate mathematical model of the milled mixture of sugar cane.

Highlights

The milling process of sugar cane is very complicated, prepared cane are milled into bagasse, the bagasse is sprayed or soaked with dilute juice and passed through up to several further mills, in a counter current extraction process, with a further spraying or soaking process occurring before each subsequent mill
The milled mixture of sugar cane was treated as porous medium solid-liquid two-phase materials, and researchers had established the constitutive model and theoretical framework of fluid-solid coupling by finite element analysis, and applied it to the numerical simulation of the milling process (Owen et al, 1995, 1998)
In view of elastoplastic coupling phenomenon in the milling process, a mechanical model of elastoplastic coupling of the milled mixture of sugar cane was established by modified Drucker-Prager Cap (DPC) model and parameters evolution and verified by uniaxial compression test and finite element analysis

Summary

Introduction

The milling process of sugar cane is very complicated, prepared cane are milled into bagasse, the bagasse is sprayed or soaked with dilute juice and passed through up to several further mills, in a counter current extraction process, with a further spraying or soaking process occurring before each subsequent mill. For accurate analysis of operating parameters and efficiency of the milling process, it is necessary to establish a mathematical model, and the key to the model is the constitutive relationship of the milled mixture of sugar cane (Owen et al, 1995). The milled mixture of sugar cane was treated as porous medium solid-liquid two-phase materials, and researchers had established the constitutive model and theoretical framework of fluid-solid coupling by finite element analysis, and applied it to the numerical simulation of the milling process (Owen et al, 1995, 1998). Researchers used finite element method to predict the internal energy dissipation of solid substrate deformation and liquid flow during the milling process based on modified Drucker-Prager Cap (DPC) model, but the results need to be tested (Adam & Loughran, 2005; Loughran & Kannapiran, 2005). Someone made the uniaxial compression tests and shear tests, employed the parameter estimation package called PEST to determine the material parameters of the milled mixture of sugar cane after multiple milling (Plaza, 2013a, b)

Methods

Results

Conclusion