Separation of elastoviscoplastic strains of rock and a nonlinear creep model

Yanlin Zhao, Lianyang Zhang, Weijun Wang, Wen Wan, Wenhao Ma

Research output: Research - peer-reviewArticle

Abstract

A series of triaxial creep tests were carried out on fractured limestone specimens under multilevel loading and unloading cycles to capture elastoviscoplastic strain components. A new data processing algorithm was proposed to analyze the experimental data, determine the instantaneous elastic and instantaneous plastic strain components and the viscoelastic and viscoplastic strain components from the total strain, and separate the viscoelastic and viscoplastic strain curves from the total creep strain curve. The instantaneous elastic strain, instantaneous plastic strain, viscoelastic strain, and viscoplastic strain versus deviatoric stress relationships are highly nonlinear. The proportion of the viscoplastic strain component in the total creep strain increases with increased deviatoric stress. On the basis of the experimental results, a nonlinear elastoviscoplastic (EVP) creep constitutive model was proposed by connecting a Hooke body, a parallel combination of Hooke and St. Venant bodies, a Kelvin body, and a generalized Bingham body. The proposed EVP creep model can describe both the loading and unloading creep behavior precisely. The creep model curves agree very well with the experimental results and give a precise description of the full stages of creep, especially the tertiary creep stage. Moreover, the variation law of the creep parameters is also supported by the experimental observations. So the validity and great practical potential of the proposed EVP creep model are shown well.

LanguageEnglish (US)
Article number04017129
JournalInternational Journal of Geomechanics
Volume18
Issue number1
DOIs
StatePublished - Jan 1 2018

Fingerprint

creep
rock
rocks
unloading
plastic
plastics
limestone
parameter
test
testing

Keywords

  • Creep model
  • Creep test
  • Elastoviscoplastic behavior
  • Multilevel loading and unloading cycles

ASJC Scopus subject areas

  • Soil Science

Cite this

Separation of elastoviscoplastic strains of rock and a nonlinear creep model. / Zhao, Yanlin; Zhang, Lianyang; Wang, Weijun; Wan, Wen; Ma, Wenhao.

In: International Journal of Geomechanics, Vol. 18, No. 1, 04017129, 01.01.2018.

Research output: Research - peer-reviewArticle

@article{4b523d4156b642db9af12dd7497991f4,
title = "Separation of elastoviscoplastic strains of rock and a nonlinear creep model",
abstract = "A series of triaxial creep tests were carried out on fractured limestone specimens under multilevel loading and unloading cycles to capture elastoviscoplastic strain components. A new data processing algorithm was proposed to analyze the experimental data, determine the instantaneous elastic and instantaneous plastic strain components and the viscoelastic and viscoplastic strain components from the total strain, and separate the viscoelastic and viscoplastic strain curves from the total creep strain curve. The instantaneous elastic strain, instantaneous plastic strain, viscoelastic strain, and viscoplastic strain versus deviatoric stress relationships are highly nonlinear. The proportion of the viscoplastic strain component in the total creep strain increases with increased deviatoric stress. On the basis of the experimental results, a nonlinear elastoviscoplastic (EVP) creep constitutive model was proposed by connecting a Hooke body, a parallel combination of Hooke and St. Venant bodies, a Kelvin body, and a generalized Bingham body. The proposed EVP creep model can describe both the loading and unloading creep behavior precisely. The creep model curves agree very well with the experimental results and give a precise description of the full stages of creep, especially the tertiary creep stage. Moreover, the variation law of the creep parameters is also supported by the experimental observations. So the validity and great practical potential of the proposed EVP creep model are shown well.",
keywords = "Creep model, Creep test, Elastoviscoplastic behavior, Multilevel loading and unloading cycles",
author = "Yanlin Zhao and Lianyang Zhang and Weijun Wang and Wen Wan and Wenhao Ma",
year = "2018",
month = "1",
doi = "10.1061/(ASCE)GM.1943-5622.0001033",
volume = "18",
journal = "International Journal of Geomechanics",
issn = "1532-3641",
publisher = "American Society of Civil Engineers (ASCE)",
number = "1",

}

TY - JOUR

T1 - Separation of elastoviscoplastic strains of rock and a nonlinear creep model

AU - Zhao,Yanlin

AU - Zhang,Lianyang

AU - Wang,Weijun

AU - Wan,Wen

AU - Ma,Wenhao

PY - 2018/1/1

Y1 - 2018/1/1

N2 - A series of triaxial creep tests were carried out on fractured limestone specimens under multilevel loading and unloading cycles to capture elastoviscoplastic strain components. A new data processing algorithm was proposed to analyze the experimental data, determine the instantaneous elastic and instantaneous plastic strain components and the viscoelastic and viscoplastic strain components from the total strain, and separate the viscoelastic and viscoplastic strain curves from the total creep strain curve. The instantaneous elastic strain, instantaneous plastic strain, viscoelastic strain, and viscoplastic strain versus deviatoric stress relationships are highly nonlinear. The proportion of the viscoplastic strain component in the total creep strain increases with increased deviatoric stress. On the basis of the experimental results, a nonlinear elastoviscoplastic (EVP) creep constitutive model was proposed by connecting a Hooke body, a parallel combination of Hooke and St. Venant bodies, a Kelvin body, and a generalized Bingham body. The proposed EVP creep model can describe both the loading and unloading creep behavior precisely. The creep model curves agree very well with the experimental results and give a precise description of the full stages of creep, especially the tertiary creep stage. Moreover, the variation law of the creep parameters is also supported by the experimental observations. So the validity and great practical potential of the proposed EVP creep model are shown well.

AB - A series of triaxial creep tests were carried out on fractured limestone specimens under multilevel loading and unloading cycles to capture elastoviscoplastic strain components. A new data processing algorithm was proposed to analyze the experimental data, determine the instantaneous elastic and instantaneous plastic strain components and the viscoelastic and viscoplastic strain components from the total strain, and separate the viscoelastic and viscoplastic strain curves from the total creep strain curve. The instantaneous elastic strain, instantaneous plastic strain, viscoelastic strain, and viscoplastic strain versus deviatoric stress relationships are highly nonlinear. The proportion of the viscoplastic strain component in the total creep strain increases with increased deviatoric stress. On the basis of the experimental results, a nonlinear elastoviscoplastic (EVP) creep constitutive model was proposed by connecting a Hooke body, a parallel combination of Hooke and St. Venant bodies, a Kelvin body, and a generalized Bingham body. The proposed EVP creep model can describe both the loading and unloading creep behavior precisely. The creep model curves agree very well with the experimental results and give a precise description of the full stages of creep, especially the tertiary creep stage. Moreover, the variation law of the creep parameters is also supported by the experimental observations. So the validity and great practical potential of the proposed EVP creep model are shown well.

KW - Creep model

KW - Creep test

KW - Elastoviscoplastic behavior

KW - Multilevel loading and unloading cycles

UR - http://www.scopus.com/inward/record.url?scp=85033608918&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85033608918&partnerID=8YFLogxK

U2 - 10.1061/(ASCE)GM.1943-5622.0001033

DO - 10.1061/(ASCE)GM.1943-5622.0001033

M3 - Article

VL - 18

JO - International Journal of Geomechanics

T2 - International Journal of Geomechanics

JF - International Journal of Geomechanics

SN - 1532-3641

IS - 1

M1 - 04017129

ER -