A Methodology for Evaluating Structure-Borne Road Noise Prior to a Development Mule Using Direct Force Measured on a Suspension Rig

摘要

With the continuous increase of the market share of electrical and hybrid vehicles, road-induced noise within a vehicle has become a major NVH issue. Many studies have been conducted quantifying road noise through transfer path analysis (TPA) using the matrix inversion method and dynamic stiffness method thereby. However, the matrix inversion method is a calculation that always contains error, even when treated with best condition number found by trial and error iteration to match the calculation SPL to measured SPL. Furthermore, the caveat of the dynamic stiffness method is that it requires accurate dynamic stiffness value up to the frequency range of interest, which, in reality, is rarely available and is challenging to seize. TPA using these two methods is only possible when a complete vehicle is available. For the sake of cost and time reduction, circumventing these limitations is extremely critical within the vehicle production period. The main focus of this study is to directly obtain the operational forces at suspension mounting points neglecting the effect of the vehicle body through a special suspension rig. The suspension rig is verified through a comparative analysis with the actual baseline vehicle measurement up to 250 Hz.