基于FSI系统的(u_i,p)格式大型渡槽动力分析

Dynamic Analysis of Large Aqueduct Based on Format (u_i,p) of FSI System

槽体固体以位移为基本未知量,槽内水体以流场压力p为基本未知量,用能量变分原理推导了流固耦合(FSI)系流有限元分析的(ui,p)格式,给出流固耦合系统的动力特性方程,并基于FSI系统的(ui,p)格式建立渡槽槽体-水体-槽墩-基础-地基系统的力学模型,采用非对称模态提取法求解了渡槽的动力特性,并用隐式-显式积分算法计算了强震作用下大型渡槽的动力响应。计算结果表明,基于(ui,p)格式的流固耦合系统有限元分析的格式,考虑到槽体与水体的相互作用,简化了计算模型,提高了计算精度,同时也得出不同过水量下槽体结构动力特性和动力响应的变化规律等结论。

A dynamic characteristic equation is given, in which two basic unknown variables（aqueduct displacement ui and water pressure p） are let in, and the coupling format（ ui,p） with finite element analysis （FEA） of fluid-solid interaction（FSI） derived from energy variational principle is adopted. And on the basis of FEA＇s format（ ui,p ） of the FSI system, a dynamics model describing a aqueduct body-water-pier of aqueduct-fundation-ground coupling system based on the format （ ui, p） of FSI system is established, the dynamic properties of the aqueduct are obtained hy using asymmetric algorithm, and the dynamic response of the aqueduct under the action of dynamic loads is calculated by adopting the implicit-explicit integration algrithm. The calculated results indicate that by adopting the fluid-solid coupling system with FEA based on the format （ui, p ）, the calculation model is simplified and its calculating accuracy improved, and mean while, the laws of dynamic characteristics and respone of the aqueduct structure ur^der different discharges are obtained.