Authors: Akın Oktav; Günay Anlaş; Çetin Yılmaz
Addresses: Vibration and Acoustics Laboratory, Boğaziçi University, Sarıyer 34470, İstanbul, Turkey ' Department of Mechanical Engineering, Boğaziçi University, Bebek 34342, İstanbul, Turkey ' Department of Mechanical Engineering, Boğaziçi University, Bebek 34342, İstanbul, Turkey
Abstract: In this work, vehicle noise variability and dominant paths that cause low frequency booms are investigated. Five identically produced vehicles are subjected to road tests to acquire engine and exhaust mounts' acceleration and cabin sound pressure level (SPL) data. When the acquired data are processed, significant variability is observed among SPLs of vehicles. Low frequency booms are also diagnosed and two of the tested vehicles are selected to be further analysed. Structural transfer path analysis (TPA) is carried out, in which several parameters such as test conditions and frequency response function estimation procedures are highlighted. Dominant paths that contribute to booms are identified. To diagnose the cause of variability, a systematic approach is proposed, where all steps consist of experimental studies only. Finally, it is deduced that predominant paths, which are found to be main contributors of diagnosed booms, are also the root causes of variability observed.
Keywords: noise variability; measurement variability; structural TPA; transfer path analysis; booming; source-path-receiver model; vehicle noise variability; low frequency booms; engine mounts; exhaust mounts; acceleration; cabin sound pressure levels.
International Journal of Vehicle Design, 2016 Vol.71 No.1/2/3/4, pp.300 - 320
Received: 08 Nov 2014
Accepted: 28 Nov 2015
Published online: 02 Sep 2016 *