The effect of fluid-solid coupling on wave scattering computed with the Wave Based Method

The Wave Based Method (WBM) presents an efficient numerical method to compute the steady-state solution of boundary value problems. The system’s response is approximated by weighted wave functions, which fulfil the underlying differential equations. It is revealed for poroelastic problems in the field of vibro-acoustics, that the WBM converges very fast and needs significantly less degrees of freedom than a finite element procedure. To benefit from these advantages in the computation of wave scattering in water saturated soil, the WBM is extended by a formulation of the Biot theory, which is based on the description of the displacements for the solid skeleton and the fluid seepage field. For the 2D case, the displacement fields consist of contributions from a P1-, P2-, and S-wave. In the scope of this contribution, a coupling approach is presented to couple the scattered wave field around an empty canyon to the free field solution of an incident wave front in the frequency domain. The WBM is briefly introduced and the formulation of the displacements and stresses based on wave functions is depicted. Moreover, an example from literature is chosen to assess the accuracy of the implemented WBM approach. The wave based procedure is involved in a Fourier synthesis approach to evaluate the system’s response in the time domain. The example of a layered soil with an empty canyon and incident S-wave, described by a Ricker wavelet, is chosen. On the basis of this model, the impact of fluid-solid coupling on horizontal and vertical displacements along the surface of the structure is discussed.     «

The Wave Based Method (WBM) presents an efficient numerical method to compute the steady-state solution of boundary value problems. The system’s response is approximated by weighted wave functions, which fulfil the underlying differential equations. It is revealed for poroelastic problems in the field of vibro-acoustics, that the WBM converges very fast and needs significantly less degrees of freedom than a finite element procedure. To benefit from these advantages in the computation of wave sca...     »