A seismic free field input model for
FE-SBFE coupling in time domain
Yan Junyi (阎俊义), Jin Feng (金峰), Xu Yanjie (徐艳杰), Wang Guanglun (王光纶) and
Zhang Chuhan (张楚汉)
Department of Hydraulic Engineering, Tsinghua University, Beijing 100084,
China
Abstract: A seismic free field input formulation of the coupling
procedure of the finite element (FE) and the scaled boundary finite-element (SBFE)
is proposed to perform the unbounded soil-structure interaction analysis in time
domain. Based on the substructure technique, seismic excitation of the
soil-structure system is represented by the free-field motion of an elastic
half-space. To reduce the computational effort, the acceleration unit-impulse
response function of the unbounded soil is decomposed into two functions: linear
and residual. The latter converges to zero and can be truncated as required.
With the prescribed tolerance parameter, the balance between accuracy and
efficiency of the procedure can be controlled. The validity of the model is
verified by the scattering analysis of a hemi-spherical canyon subjected to
plane harmonic P, SV and SH wave incidences. Numerical results show that the new
procedure is very efficient for seismic problems within a normal range of
frequency. The coupling procedure presented herein can be applied to linear and
nonlinear earthquake response analysis of practical structures which are built
on unbounded soil.
Keywords: soil-structure interaction; scaled boundary finite-element;
seismic excitation; time domain
