Development of nonlinear cross-anisotropic model for sands based on state parameter
来源期刊：中南大学学报(英文版)2013年第7期
论文作者：CHEN Cheng(陈成) ZHOU Zheng-ming(周正明)
文章页码：1992 - 2000
Key words：sand; state parameter; strain work-softening; nonlinear elasticity
Abstract: Numerous experimental studies reveal that the mechanical and deformational behaviors of sands are dependent on the combined effect of void ratio and stress. To predict this complex behavior of sands, a hypo-elastic model is developed based on the cross-anisotropic elasticity model, which involves four parameters: bulk module, tangent Young’s module, volume deformation coefficient and Poisson ratio. A parameter defined as virtual peak deviatoric stress dependent on state parameter is introduced into hyperbolic stress-strain relationship to determine tangent Young’s module. In addition, an existing fitting equation for isotropic compression curves and an existing dilatancy equation, which can consider the effect of state of sands, are employed to determine bulk module and volume deformation coefficient. Thirteen model constants are involved in the proposed model, the values of which are fixed for a sand over a wide range of initial void ratios and initial confining pressures. Well known experimental data for drained and undrained triaxial compression tests of Toyoura sand are successfully modeled.
CHEN Cheng(陈成), ZHOU Zheng-ming(周正明)
(State Key Laboratory of Geomechanics and Geotechnical Engineering (Institute of Rock and Soil Mechanics,
Chinese Academy of Sciences), Wuhan 430071, China)
Abstract:Numerous experimental studies reveal that the mechanical and deformational behaviors of sands are dependent on the combined effect of void ratio and stress. To predict this complex behavior of sands, a hypo-elastic model is developed based on the cross-anisotropic elasticity model, which involves four parameters: bulk module, tangent Young’s module, volume deformation coefficient and Poisson ratio. A parameter defined as virtual peak deviatoric stress dependent on state parameter is introduced into hyperbolic stress-strain relationship to determine tangent Young’s module. In addition, an existing fitting equation for isotropic compression curves and an existing dilatancy equation, which can consider the effect of state of sands, are employed to determine bulk module and volume deformation coefficient. Thirteen model constants are involved in the proposed model, the values of which are fixed for a sand over a wide range of initial void ratios and initial confining pressures. Well known experimental data for drained and undrained triaxial compression tests of Toyoura sand are successfully modeled.
Key words:sand; state parameter; strain work-softening; nonlinear elasticity
