In this study, a new procedure for solving 2-D dynamic problems of semiinfinite medium in time domain by boundary element method (BEM) is presented. For simulation of wave propagations in a 2-D regular half space including the far field effects, an infinite boundary element(IBEM) is proposed.
The shape function of the infinite boundary element is a combination of decay functions and Laguerre functions. The shape functions proposed in this study well satisfy the finiteness condition, the Sommerfeld radiation condition at infinity, and the zero convergence condition of the displacement and stress at infinity. Though the proposed shape functions have been developed for the time domain analysis, they may be also applicable to the frequency domain analysis.
Through the response analysis in a 2-D half space under a uniformly distributed dynamic load, it has been found that an excellent accuracy can be achieved compared with the analytical solution. Another example analysis of the response for the 2-D half space under a uniform load with more complex frequency component also shows very good results. The concept of the infinite boundary element may provide a powerful tool for dealing with the soil-structure interaction analysis and the wave propagation problems in multi-layered media.
