This works presents a methodology to obtain, numerically, the transfer matrix (TM) of a pipeline component with fluid-structure interaction (FSI), supported by experimental model verification and compared with well-known analytical solutions.This is achieved by extending the two-load method used to obtain the TM of a purely acoustic component to a four-load method, applied to a FEM model with FSI. Analytical models are available for singular pipeline components, but when it comes to complex shaped components, numerical and/or experimental analysis have to be performed in order to obtain a representative model of the system. One way of achieving this is by modelling the overall system in a TM method (used to describe the acoustic behaviour of a fluid contained in a pipe), which relates the state vector at two different locations of the circuit. This method can be used in a substructure fashion, where each component can be described/characterized independently by a transfer matrix. An approach exists to obtain these properties numerically from a FEM model, via the two-load method, used for a purely acoustic model, in which state vector contains two generalized quantities: velocity and pressure of the fluid. Further analysis show that neglecting FSI in some cases leads to wrong results. In this case, the state vector containing four generalized quantities, relating not only the pressure and velocity of the fluid in the inlet and outlet, but also the stress and velocity of the pipe wall is needed. A combination computational approaches with experimental verification are used to perform the characterization of such components.
