A developed dynamic elastoplastic constitutive model of soil based on the Davidenkov shear stress-strain skeleton curve

摘要

Based on the Davidenkov one dimension dynamic shear strain-stress skeleton curve, a new dynamic shear stress-strain hysteresis curve of soils is constituted by using Mashing rules. The Davidenkov skeleton curve in the constitutive model of soil is corrected by using sectional functions, and upper limit shear strain amplitude is used as the sectional point. The modified skeleton curve can be approach to the upper limit shear stress when shear strain amplitude is approach to infinite. The equations used to calculate damping ratio of soil are deducted. How the fitting parameters A, B and γ_0 of the constitutive model of soil to influent the curves of dynamic shear modulus ratio and damping ratio versus shear strain amplitude(G/G_(max)～γ and D～γ) are studied in detail. Based on these studies, a new fitting method of the parameters A, B and γ_0 is advanced to fit the tested G/G_(max)～γ and D～γ curves. It is obvious that the new fitting method is better than the general methods to fit the tested G/G_(max)～γ and D～γ curves of soils in Nanjing city. The reference values of fitting parameters A, B and γ_0 are given to fit the G/G_(max)～γ and D～γ curves of soils tested by free vibration column apparatus.