流固耦合系统位移-压力有限元格式在渡槽动力分析中的应用

Application of finite element simulation of displacement-pressure of fluid-solid interaction system for dynamic analysis of hydro-aqueducts

考虑FSI的边界条件,采用变分原理建立了流固耦合(FSI)系统的位移-压力(ui,p)有限元格式,给出流固耦合系统的动力特性方程。建立了矩型和U形渡槽的动力学分析的FSI模型,以非对称特征值求解法求解了大型渡槽的动力特性,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格式,考虑了槽体与水体的相互作用,简化了计算模型,提高了计算效率和精度,同时也得出不同过水量下两种渡槽结构动力特性和响应的变化规律等结论,可为大型渡槽及同类工程动力设计提供参考。

Taking into consideration of the boundary conditions in fluid-solid interactions （FSI）, a displacementpressure finite element formulation and the dynamic state equation of the FSI system are set up through the variation principle. Analyses are conducted, considering four depths of water in aqueduct, for large U-shape and rectangular aqueducts. The dynamic properties of the aqueduct were obtained by applying an asymmetric algorithm. The dynamic responses of large aqueducts under dynamic loads were calculated by adopting the implicit-explicit integration algorithm. The calculated results indicated that the displacement-pressure based FEA formulation of FS1 system with interaction between aqueduct and water has simplified the calculation model and improved the calculation accuracy. The variation law was formulated for the dynamic stress and displacement of the aqueduct structure under different quantities of discharge.