Experimental study of component-based transfer path analysis hybrid methods applied to a helicopter

Abstract

The noise prevailing inside the helicopter’s cabin always presents a problem for the operators of this vehicle. It is a source of annoyance and represents a pressing problem in the helicopter industry, causing manufacturers to constantly seek new technologies and solutions to reduce noise. This article aims to present a component-based transfer path analysis method (CB-TPA) and its application to the prediction of structure-borne noise transmitted into the cabin of a helicopter due to its main gearbox. The approach characterizes the source using a laboratory test bench and uses various CB-TPA methods to couple the blocked force to the dynamics of the receiving structure. The article details the used methods, their main assumptions, the experimental test configurations, and discusses the results compared to the classical in situ CB-TPA method. The effects of important parameters such as the completeness of the input and transfer mobility matrices are also discussed. It is shown that the presented methodology can correctly and accurately capture the noise in the cabin from a decoupled characterization of the source and the receiving structure.