Numerical investigation of plane wave propagation in three soil models and a simple viscoelastic treatment of the boundary considering gravity using MPM

摘要

The importance of plane wave propagation in geotechnical engineering problems considering both small and large deformation is well understood but the theory of wave propagation in the latter is maybe not mature.In this paper,the mechanism of plane wave propagation in constitutive models such as linear elastic model,Mohr Coulomb model (MC) and elastoplastic density-dependent model (DDSM) considering finite deformations is extensively studied using the material point method.The classical laws of wave propagation and reflection in a continuum are found to provide reasonable explanations to the considered problems.The stress propagation mechanism in the three models considered is mainly related to the variation of the material wave impedance.An accurate silent boundary condition is found difficult even impossible to be determined for complicated models,which is verified by a simple deduction.Moreover,a simple viscoelastic silent boundary is proposed to consider the realistic effects of gravity in geotechnical engineering problems and its performance is compared with that of the classical viscous boundary for truncating a ID linear elastic half-space.