Linear and Equivalent Linear Analysis of 1D/2D Semi-infinite Free-Field Response Using Perfectly Matched Layer

This study investigates the 1D/2D free-field response under seismic excitation by simulating radiation damping. In order to conduct linear and equivalent linear dynamic analyses, a finite element code was developed. Also, perfectly matched layer (PML) was employed to simulate semi-infinite media. Using PML cause reduction in model dimensions and computational cost without losing accuracy of responses. The 1D/2D free-field response was obtained using SV and P wave propagation for half-plane one-layer and multilayer media. The novelty of this study can be summarized as: (I) Investigation of a semi-infinite environment responses under earthquake loading using PML; (II) New approach in applying input motion to the considered 2D numerical model and simulating wave propagation; (III) Equivalent linear analysis using PML as an absorbing boundary. The responses were compared with those of the extended mesh models or other commercial well-known software. Results indicated a complete agreement in the time and frequency domains. The results also showed that the PML is effective for both pulse and earthquake input motion modes in linear and equivalent linear analyses. In addition, results showed that the method of applying excitation and corrections in FE equilibriums are well compatible with the PML formulations, and the propagation in semi-infinite media is simulated correctly.