This paper investigates the effect of the multi-directional components of ground motion on an unanchored steel storage tank. Both the liquid sloshing effect and contact behavior between the foundation and tank are included in the study. A three-dimensional model for a foundation–structure–liquid system is numerically simulated using the finite element method. The Lagrange fluid finite element method (FEM) in ANSYS is used to consider the liquid–solid interaction. In the liquid–structure–foundation interaction model, the contact and target elements are adapted to simulate the nonlinear uplift and slip effects between the tank and the foundation. Three earthquake ground motions are selected for evaluating the seismic behavior of the tank. Comparisons are made on the horizontal displacement, “elephant-foot” deformation, stress, base shear and moment, sloshing of the liquid, uplift, as well as slip behavior under the application of the unidirectional, bi-directional and tri-directional components. Under the selected ground motions, the horizontal bi-directional seismic component has great influence on the liquid sloshing in the tank studied in this paper. The vertical seismic component produces high compressive axial stress, and it also makes the uplift and slide of the tank bottom increase significantly. The applicability of this conclusion should be carefully considered when applied to other types of ground motion inputs.

中文翻译：

---

地震方向分量对无锚钢罐抗震性能的影响

本文研究了地震动的多向分量对无锚钢制储罐的影响。研究中既包括液体晃动效果，也包括基础与水箱之间的接触行为。使用有限元方法对基础-结构-液体系统的三维模型进行了数值模拟。ANSYS中的拉格朗日流体有限元方法（FEM）用于考虑液固相互作用。在液-固-基相互作用模型中，接触单元和目标单元适用于模拟储罐与基础之间的非线性隆起和滑移效应。选择三个地震地面运动来评估储罐的地震行为。比较了水平位移，“象脚”变形，应力，基础剪力和弯矩，在单向，双向和双向组件的应用下，液体的晃动，隆起以及打滑行为。在选定的地震动条件下，本文研究的水平双向地震分量对储罐中的液体晃动有很大影响。垂直地震分量产生很高的轴向压缩应力，也使罐底的隆起和滑动大大增加。当将该结论应用于其他类型的地面运动输入时，应仔细考虑该结论的适用性。本文研究的水平双向地震分量对储罐内的液体晃动有很大的影响。垂直地震分量产生很高的轴向压缩应力，也使罐底的隆起和滑动大大增加。当将该结论应用于其他类型的地面运动输入时，应仔细考虑该结论的适用性。本文研究的水平双向地震分量对储罐内的液体晃动有很大的影响。垂直地震分量产生很高的轴向压缩应力，也使罐底的隆起和滑动大大增加。当将该结论应用于其他类型的地面运动输入时，应仔细考虑该结论的适用性。