Improved frequency modeling and solution for parallel liquid-filled pipes considering both fluid-structure interaction and structural coupling

The dynamic characteristics of a single liquid-filled pipe have been broadly studied in the previous literature. The parallel liquid-filled pipe (PLFP) system is also widely used in engineering, and its structure is more complex than that of a single pipe. However, there are few reports about the dynamic characteristics of the PLFPs. Therefore, this paper proposes improved frequency modeling and solution for the PLFPs, involving the logical alignment principle and coupled matrix processing. The established model incorporates both the fluid-structure interaction (FSI) and the structural coupling of the PLFPs. The validity of the established model is verified by modal experiments. The effects of some unique parameters on the dynamic characteristics of the PLFPs are discussed. This work provides a feasible method for solving the FSI of multiple pipes in parallel and potential theoretical guidance for the dynamic analysis of the PLFPs in engineering.