Measurement of the influence of engine mount stiffness onnoise and vibration comfort in a car at idle

摘要

A bench has been designed and built to place a subject in vibration and noise conditions reproducing those of a car running at idle. The subject is submitted to vertical seatvibrations, while putting his hands on a steering wheel vibrating along the column and hearing noise through headphones. That bench has been used to conduct a pair comparison of 4 cars and two types of signals obtained from one of these cars by simulating some modifications of the stiffness of engine mounts. First of all, the contribution of each mount to the noise and vibration levels in the cabin havebeen evaluated from a Transfer Path Analysis. The results of the test have shown that the modification of the stiffness had little influence on comfort, because the contribution of mounts was rather low. The model of merit scores obtained from a previous study has also been checked, indicating its reliability.