Comparison of two methods of transfer path analysis applied to snowmobile for noise source identification

Abstract

The purpose of this paper is to propose a vibro-acoustic modeling of a snowmobile suspension in order to determine the elements and transfer paths that contribute most to the global noise of this mechanical system. Two approaches, Transfer Path Analysis (TPA) and Operational Transfer Path Analysis (OTPA) are compared. The first one consists in using measurements of mechanical impedance, the operational data, and the airborne transfer functions obtained according to the reciprocity principle. In the second approach, the airborne transfer functions are no longer measured, but are now calculated using an inverse method and operational data only. Consequently, two different matrix models for these airborne transfer functions are obtained. In both cases, the mechanical excitation forces are determined by inverse method using singular value decomposition. Finally, an experiment is set up to conclude on which approach provides the best reconstruction and identification of contributors to the radiated noise. The applicability and rapidity of each model are also discussed in the conclusion.