Accurate reconstruction of point and transfer mobilities using the round-trip method

The round trip method enables the indirect determination of point and transfer mobilities along interfaces that cannot be easily excited. One embodiment of the method requires excitation at a subset of points either side of the interface, while responses are measured along it. This is typically done by instrumented hammer or shaker. Alternatively, the excitation required can be generated by equipment operational in use, using the concept of the generalised transmissibility. In the present paper, we investigate the sensitivity of the round-trip method with respect to the number of remote measurement positions used, their locations, and signal-to-noise-ratio. Numerical and experimental examples are provided which demonstrate that there exists an optimum number of excitation and response positions for the accurate reproduction of point and transfer FRFs.