A Scaling Surface Based SBFEM for the Acceleration Unit-Impulse Response Function of 3D Non-Homogeneous Half-Space

Abstract

A computational model for the acceleration unit-impulse response function (AUIRF) of wave motion based on the scaled boundary finite element method (SBFEM) is proposed in this study for the 3D non-homogeneous half-space. In this model, a surface parallel to the structure-foundation interface for the infinite domain is defined as the scaling center. An expression of characteristic length used in the dimensionless frequency is proposed, which makes it possible to transform the derivative of dynamic stiffness at the structure-foundation interface of 3D non-homogeneous half-space with respect to spatial coordinate into that with respect to frequency. Hence, the governing equations of the AUIRF can be obtained from those of dynamic stiffness in frequency domain by the inverse Fourier transform and solved by the numerical time integration method. The accuracy of the proposed method is demonstrated by comparing the dynamic responses of the homogeneous, horizontally layered half-space, and 3D non-homogeneous half-space subjected to the near-field excitation with those obtained by the finite element method.