Nonlinear SEM numerical analyses of dry dense sand specimens under rapid and dynamic loading

摘要

The paper mainly concerns the mechanical response of 2D dry dense sand specimens under shock loading. The problem is numerically analysed by means of a SEM dynamic code, within which an already conceived non-local viscoplastic constitutive model characterized by a non-associated flow rule and by an anisotropic strain hardening has been implemented. In particular the strain localization and time dependency of the material mechanical response are taken into consideration. Both rapid/static loading and dynamic histories are numerically simulated. In the first case, the time dependency of the material mechanical response can be captured by neglecting inertial effects, while in the second one the two factors are superimposed and the propagation of the stress waves within the specimen is discussed. The interest of these analyses derives from the fact that the diffusion phenomenon takes place within a specimen already localized.