Generally,electric vehicles have excessive road booming noise under tire-road excitation.With the booming noise issue at 31Hz of an electric SUV vehicle caused by the rear axle as the research object,the vibration mode of the tire at low frequency,the force transmissibility of suspension,and the vibro-acoustic coupling effect between lift gate and body cav-ity are analyzed.The solution measures of rear suspension rigid mode adjustment,body modes control and lift gate con-straint were proposed.And the booming noise has been decreased from 45 dB(A)to 35 dB(A).Then,it was proposed to use suspension force transmissibility to measure the transmission performance of the suspension,use body noise transfer func-tion to measure the lift gate noise transfer performance,and use the noise transfer function of the lift gate to measure the cou-pling effect between the lift gate and the internal cavity.The coupling mechanism between the lift gate and the body cavity was analyzed theoretically.It is shown that the impedance matching between the lift gate and the body cavity at the first rigid mode frequency of lift gate is the root cause of SUV′s booming noise in the interval of 25-35 Hz.The analysis of road booming noise mechanism and solutions offers a guideline for NVH development of electric vehicles.
关键词
声学/路噪轰鸣声/悬架力传递率/尾门模态/声腔/声固耦合
Key words
acoustics/road booming noise/suspension force transmissibility/lift gate mode,body cavity/vibro-acoustic coupling
维普
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