车内低频路面噪声分析与控制

Analysis and Control of Low Frequency Road Noise inside a Car

某三厢轿车在粗糙的老旧沥青路面上行驶时,车内后座存在严重的低频轰鸣声。通过车内空腔声学模态和装饰车身结构模态仿真计算,发现车内后座低频噪声产生的原因为车内空腔的第二阶声学模态与装饰车身车顶后部第六阶局部结构模态强烈耦合。为避免耦合共振,改进了后车顶横梁结构设计。实车验证改进措施有效。

There is a serious booming noise in rear seats of a sedan car when the car is running on an old and rough asphalt pavement. The simulations of the interior acoustic modal of the car＇s cavity and the structural modal of the trim＇ s body show that the low-frequency noise in the rear seats is due to the strong coupling of the second-order modal of the acoustic cavity with the sixth-order local structural modal of the trim＇ s body. In order to avoid the coupling resonance, the beam structure of the rear roof was modified. This modification can effectively solve the problem of low frequency road noise inside the car.