Numerical simulation of unstructured grids discontinuous galerkin finite element method for complex surface

The study of seismic wave theory in 2D/3D complex terrain and complex media is of great significance for understanding the seismogenic mechanism and the seismogenic process. Therefore, the development of a method with high precision and high efficiency while adapting to complex terrain and complex media is essential for studying seismic wave propagation and seismic research. Discontinuous galerkin finite element method(DG-FEM) uses unstructured mesh to fit the complex model, especially the unstructured mesh can almost perfectly fit arbitrary complex terrain and complex medium, and DG-FEM also has the characteristics of high precision and low frequency dispersion. These advantages of DG-FEM have attracted more and more attention from geophysical researchers .

In this abstract, we implement the numerical simulation of the modal DG-FEM elastic wave , and compare the results with the analytical solution of the Generalized Reflection-Transmission(GRT) coefficient method. Furthermore, NPML is modified and applied to DG-FEM, which greatly reduces the impact of artificial boundaries. Compared with traditional PML, the efficiency has been greatly improved. At the same time, we realize the forward modeling of the unstructured grid DG-FEM for the complex terrain media model.