Towards the Efficient Simulation of Large‐Scale Soil‐Structure Interaction Problems Using the Scaled Boundary Finite Element Method

ABSTRACT Modeling wave propagation in soil using conventional finite element methods necessitates the simulation of extensive spatial domains to prevent reflections at artificial boundaries. Classical absorbing boundary conditions can be used to mitigate this problem, but must be placed at a considerable distance from the area of interest to ensure accuracy. Especially for three‐dimensional problems, the computational costs associated with these approaches increase significantly, making them impractical for large‐scale applications. To address this challenge, the scaled boundary finite element method (SBFEM) provides an efficient alternative by reducing the near‐field to a minimum and defining an unbounded subdomain around it. This subdomain is constructed by scaling the soil‐structure interface towards infinity, enabling the representation of infinite domains without requiring excessively large finite models. Within this framework, the reaction forces at the interface are computed using the acceleration unit‐impulse response method, introducing a convolution integral into the equations of motion governing wave propagation in the bounded domain. This contribution examines the idea of dividing the unbounded subdomain into further subdomains to enable a more efficient computation of the acceleration unit‐impulse response matrix and a faster treatment of the corresponding terms in the time solver. It focuses on the evaluation of the proposed decoupling strategy and on the assessment of the effect of the number of divisions with respect to computational efficiency and accuracy. The results underscore the potential of this strategy to enhance computational performance while maintaining acceptable accuracy, offering significant advantages regardless of the problem size.