汽车车身空腔阻隔结构降噪试验研究

Tests for noise reduction of car body cavity barrier structure

系统性地建立了阻隔结构降噪试验研究方法。建立面向白车身的阻隔结构降噪性能测量方法,通过对比阻隔结构拆除前后白车身模态与传递函数的变化情况,分析其对于车身低频噪声的抑制能力;建立面向整车的阻隔结构降噪性能转鼓试验方法,用以评估其对于发动机噪声、轮胎路面噪声的抑制能力;建立面向整车的阻隔结构降噪性能风洞试验方法,用以评估其对于气动噪声的抑制能力。试验结果表明,阻隔结构降低车内噪声主要有两个方面:一方面,空腔阻隔结构增强了车身的模态阻尼,抑制车身的振动,从而降低了车内低频噪声;另一方面,阻隔结构切断了车外噪声经过车身侧围空腔入侵乘员舱的传播途径,从而降低了车内高频噪声。

The test study methods were systematically established for noise reduction of car body cavity barrier structure.Variations of body-in-white modal features and transfer function with and without barrier structure were measured to analyze barrier structure’s suppression ability against car body low-frequency noise.The drum test method for noise reduction performance of the whole vehicle barrier structure was built to estimate barrier structure’s suppression ability against engine noise and tire/road surface noise.The wind tunnel test method for noise reduction performance of the whole vehicle barrier structure was built to estimate barrier structure’s suppression ability against aerodynamic noise.The test results showed that cavity barrier structure reducing interior noise has two aspects;on one hand,cavity barrier structure enhances car body’s modal damping to suppress car body’s vibration and reduce interior low-frequency noise;on the other hand,barrier structure cuts off the propagation path of noise from outside of vehicle through car body’s side cavity to invade passenger compartment so as to reduce interior high-frequency noise.