Love-Type Waves in Multilayered Elastic Media Containing Voids: Haskell Matrix Method

Propagation of Love-type waves is investigated in a model of multilayered elastic solid half-space containing voids. Using Haskell matrix method, the dispersion relations are derived for two situations of topmost boundary surface of the model: (a) when it is stress-free and (b) when it is rigid. For both the situations, there exist two fronts of Love-type waves that are dispersive in nature and propagating with distinct speeds. One of these wave fronts is analogous to that obtained for multilayered Cauchy elastic half-space, while the other front is new and appeared due to the presence of voids in the model. Conditions of propagation for both the fronts of Love-type waves are derived analytically for 2-layered model. Comparison of dispersion curves corresponding to both these fronts is also depicted graphically for 2- and 3-layered models with stress-free boundary surface. Effect of layer thickness and presence of void parameters is studied on the speeds of wave fronts and depicted graphically for a specific 2-layered model.