Condensation solution method for fluid-structure interaction dynamic models of structural system

In the fluid-structure dynamic analysis, the low solution efficiency seriously restricts the passive and active vibration control of structures. But so far, this issue has not been well addressed. Component mode synthesis (CMS) is an efficient method for dynamic analysis of structures. However, since the concept of mode for the fluid is very weak, the CMS is not suitable for solving fluid-structure interaction dynamic problems. Another type of dimension reduction method is dynamic condensation originating from Guyan method. In this paper, introducing the idea of CMS and combining the Guyan method, an efficient condensation solution method is proposed to solve the fluid-structure interaction dynamic models. In the dynamical modeling, both the structure field and fluid field are discretized using 20-node three dimensional elements. The elemental fluid-structure interaction equations of motion are formulated using the Hamilton principle and weighted residual method. The solid and fluid fields are divided into substructures, and all the degrees of freedom (DOFs) of the two fields are divided into interior structure DOFs, boundary structure DOFs, interior master fluid DOFs, interior salve fluid DOFs, as well as boundary fluid DOFs. In the solid substructures, higher orders of mode are neglected to realize a large-scale dimensional reduction, while for the fluid field, the slave DOFs are replaced by the master DOFs. To conduct the verification of the present method, experiment is carried out. The comparison results show the high accuracy and efficiency of the condensation solution method.