M. H. Sadd
Mech. Eng. and Appl. Mech. Dept., Univ. of Rhode Island, Kingston, RI 02881
A. J. Silva
Univ. of Rhode Island, Narragansett, RI 02882
G. E. Veyera
Univ. of Rhode Island, Kingston, RI 02881
Wave propagation in saturated granular sediments is modeled through discrete element simulation. The sediments under study are assumed to be primarily sandy, and are thus modeled as cohesionless granular material saturated with pore fluid. Numerical simulation is based on the discrete element method, a numerical scheme employing a modeling strategy to determine the translational and rotational motion of all particles in model material assemblies. For application to wave propagation, the movements of individual particles are a result of the propagation of disturbances through the media. Contact laws between adjacent particles are constructed using elastohydrodynamic lubrication theory, and these relations determine the contact force as a function of the relative displacement and relative velocity between neighboring particles. Using these new contact laws, wave motion simulations of one- and two-dimensional computer-generated model assemblies have been conducted. Results indicate that the wave speed and amplitude attenuation are functions of the physical microstructure or fabric of the discrete medium. Wave speed is inversely related to the porosity of the solid phase, while attenuation studies indicate that a branch vector distribution correlates with interparticle force transmission. Model development and simulation results will be presented.