FEM Analyses on Ratedependent Behaviors of Sand Due to Its Viscous Properties

Abstract:

Based on the experimental results from drained plane strain compression(PSC)tests on saturated sand under complex loading histories,the ratedependent behaviors of sand due to its viscous properties were studied.It was found that sand exhibits obvious loading rate effects,creep deformation and stress relaxation.When monotonic loading was restarted immediately after a stepchange in the strain rate or following a creep loading or stress relaxation stage,the stressstrain relation showed a very high tangent stiffness.A nonlinear finite element method(FEM)analysis technique was developed.In the FEM analyses,the sand was described by the threecomponent elastoviscoplastic constitutive model.It was shown that the present FEM analyses can properly simulate the global stressstrain relationships obtained from the experiments.And the whole process including the variable strain rate loadings,the creep loading and stress relaxation stages were implemented in the FEM analyses.