Finite-element numerical modeling of elastic wave on unstructured meshes

When using finite-element time-domain method for the numerical modeling of complex geological structures, the unstructured meshes can be more efficiently adapted to the space-discretization for the complex geometries. In this paper, a specific optimization for the finite-element gridding is presented according to the numerical dispersion condition in space and the stability condition in explicit time-marching scheme, making the grid size varied versus the media speed of the simulation region. The calculation for two-layer model demonstrates that the variation of grid size versus velocity can guarantee the computational efficiency and precision contemporaneously. And the calculation for complex structure model demonstrates that the finite-element scheme with unstructured meshes can be adapted to the seismic wave modeling of complex geological structures.