Experimental vibro-acoustic transfer path analysis on helicopters

The Transfer Path Analysis (TPA) presented in this paper has been performed on the Agusta Westland AW-109 helicopter. A combination of laboratory measured FRFs and in-flight operational data has been gathered: while the structural and acoustic FRFs have been collected in a measurement campaign held at Politecnico of Milan employing the helicopter mock-up, the operational data, i.e. the paths acceleration, were obtained on the actual helicopter in a succeeding session that took place in the Agusta Westland factory. Since the data analysis has brought to light some corrupted data concerning the set of the structural FRFs, an attempt to perform the TPA using POLYMAX synthesized FRFs has been brought to completion with the aim of verifying at first the reliability of such an approach and then to assess whether this technique could be employed to substitute corrupted data with synthesized ones when the database occurred to be unreliable.