Indexed by:Journal Article

First Author:Wang Zhong-chang

Correspondence Author:Wang, ZC (reprint author), Dalian Univ, Dept Liaoning Prov, Key Lab Predict & Control Complicated Struct Syst, Dalian 116622, Peoples R China.

Co-author:Yang Qing,Zhao De-shen

Date of Publication:2009-12-01

Journal:TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA

Included Journals:Scopus、ISTIC、EI、SCIE

Document Type:J

Volume:19

Issue:SUPPL. 3

Page Number:S811-S818

ISSN:1003-6326

Key Words:isotropic damage; orientation of localization; maximum hardening modulus; bifurcation; uniaxial sample

Abstract:To obtain the damage effect in the process of elasto-plasticity deformation of quasi-brittle materials, the isotropic damage loading-unloading function and damage variable were introduced to non-continuous bifurcation. The critical bifurcation orientation and its corresponding hardening modulus for quasi-brittle materials were derived considering the effect of stiffness degradation and volumetric dilatancy under the assumption of isotropic damage. The relationships of localized orientation angle and maximal hardening modulus dependent on degree of damage and initial Poisson's ratio of rock were explored. Comparative analyses were conducted to study the bifurcation of uniaxial tension-compression samples under the conditions of plane stress and plane strain. It is shown that as the initial Poisson's ratio or degree of damage increases, the localization orientation angle of the plane uniaxial compression sample tends to be initiated to decrease. However, the localization orientation angle of the plane uniaxial tension sample tends to be initiated to increase. The sum of orientation angle under tension and compression conditions is 90 degrees. There are plane stress and plane strain cases of the maximum hardening modulus that is independent of the uniaxial compression and tension.