A numerical proof-test of finite element method to simulate wave propagation in ground soil

A numerical case study is presented in this paper to demonstrate the feasibility of a finite element method with artificial boundary condition to simulate the wave in 3D ground soil. An unit centralized harmonic excitation at surface is adopted with four frequencies. The calculated vibration amplitudes are compared with the corresponding results by dynamic Green Function in frequency-wave number domain. The result shows a clear calculation error phenomena that the smaller mesh adopted, the smaller error is for a given frequency, and the lower frequency excited so the smaller error is for a given mesh size. A preliminary suggestion is presented as that the maximum mesh size of a 3D discrete grid must be no larger than 1/25 of the minimum wave length.