Absorbing boundary conditions for wave propagation in viscoelastic material.

The local absorbing boundary conditions for the wave propagation in Maxwell type viscoelastic materials (VABC-M) proposed by Badry and Ramancharla (2018) are promising in absorbing the wave propagation magnitude when mass proportional damping was present in the medium. It was also specified that an approach is not suitable when damping proportional to response frequency (stiffness) is present in the medium. In this study, local absorbing boundary conditions for a viscoelastic medium are evaluated when only damping proportional to stiffness is present in the medium (VABC-S). Later, the study was extended to include both stiffness and mass proportional damping (VABC). 1D wave propagation analysis is presented which us carried out using explicit time integration, and the results are presented. From the results, it is observed that when damping with stiffness proportional is present in material, the reflections with VABC-M are higher than the standard absorbing boundary conditions, and when mass proportional damping is included in the material, the reflections with VABC-Sare higher than the standard absorbing boundary conditions. However, VABC performs excellently in absorbing the outwardly propagating wave energy. Sensitivity analysis is carried out to verify load frequencies against the design frequency. It is concluded that the VABC performs excellently for load frequencies higher than the design frequencies. [ABSTRACT FROM AUTHOR]