In situ measurement of the blocked force of structure-borne sound sources

It is shown that the blocked force of a structure-borne sound source can be obtained from measurements made in situ, i.e. when the source is connected to a receiver structure. This potentially removes the need for special test rigs employing blocked terminations. A corollary of this relationship is that a theoretically exact ‘in situ transfer path analysis’ is possible with a fully assembled structure, such as a vehicle, without at any stage needing to separate the substructures. The results are validated by numerical simulation and measurement on beam-like sources and receivers.