高阶晃动振型对LNG储罐地震响应的影响

Effect of high order sloshing mode on seismic response of LNG storage tank

为了研究高阶晃动振型对LNG储罐地震响应的影响,考虑高阶晃动振型,建立LNG储罐的简化力学模型,推导LNG储罐的运动控制方程,给出了LNG储罐的基底剪力、倾覆弯矩和储罐内液体晃动波高的表达式。以某16×104 m3 LNG储罐为例,采用大型通用有限元分析软件ADINA System对其进行有限元模型分析,验证其修正模型的有效性,结果表明:高阶晃动振型对基底剪力和倾覆弯矩几乎无影响,但对晃动波高影响显著,尤其是长周期地震动作用下,并且考虑高阶晃动振型的晃动波高存在延时效应。提出的简化力学模型修正公式与有限元分析结果吻合较好,可以准确地预测LNG储罐地震响应。

In order to study the effect of high order sloshing modes on the seismic responses of the LNG storage tank,a simplified mechanical model of the LNG storage tank is proposed by considering the high order sloshing modes.The governing equation of the motion of the LNG storage tank is derived,and the expressions of the base shear force and the overturning moment of the LNG storage tank and the sloshing wave height of the liquid in the storage tank are given.By using the large-scale general finite element analysis software ADINA System,numerical simulation analysis is conducted on a 16×104 m3 LNG storage tank to verify the effectiveness of the revised model.The results show that the high order sloshing modes have little effect on the base shear force and the overturning moment,but have a significant effect on the sloshing wave height,especially subjected to the long-period ground motions.Besides,the sloshing wave height with the high-order sloshing mode has a delayed effect.The revised formulae of the simplified mechanical model presented in this study are in good agreement with the numerical simulation results,and can be used to accurately estimate the seismic responses of the LNG storage tank.