An explicit ABAQUS toolbox for soil-structure interaction analysis in localized regions

Abstract

The numerical simulation of soil-structure interaction (SSI) in unbounded media requires truncating the semi-infinite domain to create a finite computational domain. Consequently, absorbing boundary conditions (ABCs) and seismic input methods emerge as pivotal challenges. Currently, two technologies, the perfectly matched layers (PMLs) and the domain reduction method (DRM), are robust solutions to address these challenges. However, only a limited number of studies, all using implicit algorithms, have explored its application, which exhibits significant drawbacks in large-scale computations. An explicit dynamic analysis is computationally efficient for the large-scale simulations with relatively short dynamic response times and for the analysis of extremely discontinuous events. To this end, we propose an explicit formulation of the Perfectly Matched Layer (PML) based on an extended central difference method. We implement the formulation in ABAQUS/EXPLICIT through the user-defined element (VUEL) subroutine and the user predefined field (VUFIELD) subroutine. Meanwhile, we implement the DRM by developing a Python package to calculate equivalent nodal forces. Finally, several numerical experiments in the time domain demonstrate the accuracy and stability of these implementations for both 2D and 3D domains.