Instability of gradient dependent elasto-viscoplasticity for clay

✍ Scribed by Aifantis, E. C.; Oka, F.; Yashima, A.; Adachi, T.

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 158 KB
• Volume: 23
• Category: Article
• ISSN: 0363-9061
• DOI: 10.1002/(sici)1096-9853(19990825)23:10<973::aid-nag20>3.0.co;2-m

✦ Synopsis

A gradient-dependent viscoplastic constitutive model for water saturated clay is proposed to describe the strain localization phenomena and pattern formation during deformation. Second-and fourth-order gradients of volumetric viscoplastic strain are introduced into the constitutive equations to account for the non-local e!ects due to the motion of microstructures. A linear perturbation analysis is applied to this model. The instability of the government equations (i.e. the constitutive equations and the equations of motion for the clay skeleton and pore water) is discussed for both the one-dimensional and the twodimensional situations. In addition, issues concerned with the formulation of boundary value problems by "nite element analysis in relation to the formulation and the boundary conditions are presented.