A dual-surface damage model and evaluation for natural soils within the thermomechanical framework

Abstract

Naturally deposited or residual soils exhibit more complicated behavior than remolded clays. A dual-surface damage model for structured soils is developed based on the thermodynamics framework established in our first paper. The shift stresses and the transformation between the generalized dissipative stress space and actual stress space are established following a systematic procedure. The corresponding constitutive behavior of the proposed model is determined, which reflects the internal structural configuration and damage behavior for geomaterials. Four evolution variables k i j (i = D, R; j = V, S) and the basic parameters λ, s, ν and e0 are introduced to account for the progressive loss of internal structure for natural clays. A series of fully triaxial tests and isotropic compression tests are performed for structured and reconstituted samples of Beijing and Zhengzhou natural clays. The validation of the proposed model is examined by comparing the numerical results with the experimental data.

Damage Model for Dissipative Materials with Generalized Non-Linear Strength Theory

“…, φ φ for Clay specimen is around 44-480 and 33-390 respectively. A summary of the model parameters is shown in Table 1 [7][8].…”

“…Table 1 Identified model parameters and physical properties of the specimens [6][7][8] Using the transitional stress space transform the failure function on the meridian plane into the linear function [9][10][11][12]. The proposed model of revised by the generalized non-linear strength theory in the tri-axial compression condition are given: The stress-stain relations between the proposed Fig.…”

“…Recently, the time-independent constitutive modeling for porous and multi-phase nanocrystalline materials and a simple phenomenological model for describing the macroscopic constitutive response of ferroelectric materials have been developedin the correlative field. Many researches have focused the different graded mineralogies and physico-chemical effect on geomaterials behaviour in accordance with the conventional critical state framework [5][6][7][8]. But the isotropic plasticity model with one single yield surface commonly omitted the effect caused by shearing plasticity and failed to solve some boundary value problems.…”

“…The modified constitutive models (Lade, Krieg, Morz, Defalias, Duncan-Chang, Zienkiewicz et al [1975][1976][1977][1978][1979][1980][1981][1982][1983][1984][1985] used two or more surfaces to describe more detailed elastoplastic behaviour for soils. As the effect of grain contact and crushing is becoming prevalent in the mechanism study both for sands and clays., a proposed dual-surface damage model [7][8], which satisfies the thermodynamics law and despite the complex and uncertain mineralogy form, is developed to consider the structural configuration and damage behaviour for soils. A series of drained and undrained triaxial shearing tests have been performed on laboratory samples to examine performance of the model.…”

Application the Thermomechanical Damage Modeling Approach with Generalized Non-Linear Strength Theory

“…for energy function. Differentiating the energy function and dissipation or yield functions with respect to the appropriate variables, the total 32different possibilities of constitutive equations [4] for corresponding hyperplastic damage model can be completely illustrated.…”