Effect of oblique incidence angle and frequency content of P and SV waves on the dynamic behavior of liquid tanks

Abstract

The dynamic behavior of liquid tanks is very different from those of other structures. Great effort has been put into the study of water tanks under vertical incident ground motion, but studies are still lacking regarding how different incidence angles influence the dynamic characteristics. This paper developed a model for the tank-soil-fluid system to study the variation and distribution of impulsive, convective, and total hydrodynamic pressures on the tank wall duel to water when subjective to earthquakes from different angles of incidence. The role of earthquake type (P or SV waves) and frequency contents are also considered. The tank-fluid interaction is modelled by the coupled acoustic-structural approaches. With the viscous-spring artificial boundary, the ground motions of oblique incidence can be transformed into the forces acting on the nodes of the truncated boundary of the finite-element model. It is concluded that the response of the tank-soil-fluid system is highly sensitive to incidence angles, earthquake type (P or SV waves), and earthquake record frequency contents. Therefore, in the design of tanks, not only the characteristics of the tank should be considered, but also the seismic characteristics should be considered.