A Viscoelastic Weighted Artificial Boundary for Multisource Scattering Problems

Abstract

Multisource scattering problems in simulating seismic wave inputs to structures, such as large-span bridges, remain a longstanding challenge. To address this issue, a viscoelastic weighted artificial boundary is proposed based on the assumption of an infinite linear-elastic medium; in addition, its spring and damping coefficients were derived using the apparent velocity and wave-field separation theory. A few examples of single- and multi-source models were used to analyse the accuracy of the proposed boundary, considering the influence of the scattering source location and source count. The numerical results demonstrated that the accuracy of the proposed boundary was higher than that of comparable approaches for the same problems. In multisource examples, the accuracy could be improved by approximately 20% in most cases, whereas in cases with a large source distance and uneven spatial distribution, the accuracy could be further improved by approximately 40%. These results confirm that the proposed solution can effectively simulate earthquake ground motion inputs for multipoint sources with large source distances and uneven spatial distributions.