An Equivalent Far-Field Dynamic-Artificial-Boundary Condition and its Accuracy Studies

Abstract

In order to eliminate some problems of ordinary artificial boundary conditions in soil-structure dynamic interaction analysis at present, such as plenty amount of work required in establishing viscous boundary and viscous-elastic boundary and the expensive computing hours cost in traditional far-field artificial boundary condition, an equivalent far-field artificial boundary condition for dynamic analysis was proposed based on the wave propagating theory and the reflection and transmission principle of wave on the interface of medium by setting a fully-transmitting layer and lower the speed of wave considerably propagating within it. Then numerical simulations and studies of factors affecting accuracy for equivalent far-field artificial boundary condition were conducted with FEM. Researches show that equivalent far-field artificial boundary is as nearly accurate as viscous boundary; it can overcome the problems of viscous boundary, viscous-elastic boundary and traditional far-field boundary mentioned above; it is very convenient to operate and realize; it is very efficient and low-cost in workforce. The equivalent far-field boundary proposed can be applied to engineering dynamic field such as anti-seismic of structures, vibration and impact etc.