The application of power-based transfer path analysis to passenger car structure-borne noise

Abstract

Structure-borne noise in a passenger car is usually transmitted through multiple and/or multi-dimensional paths. Therefore, identification and control of these transfer paths are effective measures for noise reduction. A power-based transfer path analysis methodology is proposed for this purpose. First, the power flow of each transfer path is estimated with an equivalent-uncoupled-system method based on linear network theory and the Thevenin equivalent theorem. Next, the correlation between the power flow of each transfer path and the sound pressure in the passenger compartment is established; then the contribution of each transfer path is ranked; meanwhile the dominant paths and their key parameters are identified through the equations of power flow calculation. Finally, these key parameters can be analysed and then improved to reduce the structure-borne noise. An illustration of this methodology is given with a passenger car model containing a power plant, three mounts, a compliant car body, and an enclosed acoustic cavity. It is demonstrated that the methodology is effective to analyse and control the structure-borne noise transfer paths.

Low-noise structure optimization of a heavy commercial vehicle cab based on approximation model

“…However, the concerned frequency is from 20 to 200 Hz given that this frequency range covers the typical running frequency and is the main frequency band of cab structure-borne noise. 18,19 When sampling vibration acceleration and sound pressure, the recording time is set at 30 s and the test is repeated thrice. The measurements of the vibration accelerations and sound pressure are illustrated in Figure 4.…”

Vibration source identification of a heavy commercial vehicle cab based on operational transfer path analysis

“…The latter noise control method is receiving increasing attention from researchers and engineers who focus on vibration and noise control. 15–17…”

“…The latter noise control method is receiving increasing attention from researchers and engineers who focus on vibration and noise control. [15][16][17] A vibro-acoustic system comprises four parts, namely, vibration source, transfer path, noise source, and receiver. For the cab vibro-acoustic system of a heavy commercial vehicle, engine and wheels are the vibration sources; cab walls are the noise sources because they radiate noise; the connecting structure between the vibration source and the noise source, such as the mounts of engine and cab, is the transfer path; and the drivers or passengers in the cab are the receivers.…”