Numerical modeling of the constitutive relationship of a soft rock using a 3-D elastic visco-plastic model

Lijun Su, Hongjian Liao, Jianhua Yin

Research output: Journal article publicationConference articleAcademic researchpeer-review

1 Citation (Scopus)


In this paper, a diatomaceous soft rock is studied. Triaxial tests had been conducted on this soft rock. From the test results, it is found that the stress-strain curve of this soft rock has a notable strain-softening tendency. In order to study its time-dependent stress-strain behavior, a constitutive model that can describe not only the strain-hardening behavior, but also the strain-softening behavior must be constructed. Based on Perzyna's fundamental assumptions of the elastic visco-palstic theory, a visco-plastic flow rule, and Yin and Graham's 3-D elastic visco-palstic constitutive model (3-D EVP model), the constitutive formulation under a triaxial stress state is obtained in this paper. The derived formulation can be used to simulate the time-dependent stress-strain behavior of both consolidated undrained and consolidated drained triaxial tests of soils and rocks. In this paper, the constitutive formulation is used to simulate the time-dependent stress-strain behavior of consolidated undrained triaxial tests of the soft rock studied in this paper. The simulated results are compared with the triaxial test results. The comparison of the results shows that model predictions agree well with measured results. This demonstrates that the EVP model can be used to describe the time-dependent stress-strain behavior of the soft rock studied in this paper.
Original languageEnglish
Pages (from-to)723-728
Number of pages6
JournalKey Engineering Materials
Issue numberI
Publication statusPublished - 27 Jul 2004
EventAdvances in Fracture and Failure Prevention: Proceedings of the Fifth International Conference on Fracture and Strength of Solids (FEOFS2003): Second International Conference on Physics and Chemistry of Fracture and Failure Prevention (2nd ICPCF) - Sendai, Japan
Duration: 20 Oct 200322 Oct 2003


  • Consolidated undrained triaxial test
  • Constitutive relationship
  • Equivalent time
  • Soft rock
  • Strain softening
  • Time-dependent

ASJC Scopus subject areas

  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering

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