Numerical Formulation to Study Fluid-Solid Interfaces Excited by Elastic Waves

In this paper,the scattering of elastic waves in a fluid-solid interface is researched. The Indirect Boundary Element Method (IBEM) was used to study this wave propagation phenomenon in a 2D fluid-solid model. The source, represented by a Hankel's function of the second kind, is always applied in the fluid. This approximate boundary integral technique is based upon the integral representation for scattered elastic waves using single-layer boundary sources. The approach presented is usually called IBEM as the sources' strengths should be obtained as an intermediate step. This indirect formulation can give a deep physical insight to the analyst on the generated diffracted waves, because it is closer to the physical reality and can be regarded as a realization of Huygens' Principle, which mathematically is fully equivalent to the classical Somigliana's representation theorem. In order to gauge accuracy, the method was tested by comparing it to an analytical solution. A near interface pulse generates scattered waves that can be registered by sensors located in the fluid. Results are presented in time domain, where several aspects related to the different wave types that emerge from this kind of problems are pointed out.