考虑流固耦合的水中结构物地震反应方法

Seismic response of underwater structure considering fluid-structure interaction

基于运动控制体的雷诺输运定理,采用任意拉格朗日-欧拉描述推导控制流体运动的Navier-Stokes方程;提出考虑流固耦合效应的水中结构物地震反应计算方法,并以水中垂直板的地震反应为例,阐明流固耦合体系的求解方法。分析地震动频率和水深对场地土-结构-流水构成的流固耦合系统动力反应的影响,结果表明:采用不可压缩流算法的Navier-Stokes方程能够合理模拟流场的位形变化,并保证流固耦合计算的收敛;考虑流固耦合作用使得结构地震反应幅值明显增大,并使频谱特性发生改变;水深对流固耦合效应的影响较大,并具有明显的非线性特征。

Based on Reynolds transport theory, Navier-Stokes equations governing fluid motion are set up with arbitrary Lagrangian-Eulerian description. Analysis methods of underwater structure seismic response with considering fluid-structure interaction are presented, and seismic response of a vertical plate is taken as an example to show the solving process of fluid-structure interaction system. Also in the analysis, the effects of seismic frequency and water depth on fluid-structure interaction system made up of site soil, structure and water are studied. The result indicated that Navier-Stokes equations using incompressible method can simulate motion of fluid domain and insure computing convergence in fluid-structure interaction analysis process. It also show that peak values of structure seismic response are larger, and frequency spectrum characteristics are also changed with the consideration of fluid-structure interaction. Water depth has great effect on fluid-structure interaction and has clear nonlinear feature.