车身双层板隔声性能分析和计算研究

Analysis and Calculation of Sound Insulation Performance of the Double-layer Board of a Car Body

参考白车身双层板的结构尺寸,设计4个具有代表性的双层板方案,通过试验对比各方案的隔声曲线,分析车身双层板结构对双层板隔声量的影响。研究结果表明增加双层板厚度对双层板隔声量的提升作用有限,但增加双层板两块板之间的空腔厚度可以控制双层板的临界频率向低频移动,提高目标频段的隔声量;提高双层板表面的折弯凸起会改变其模态,进而显著改变双层板各频段的隔声量。使用hybrid FE-SEA(Hybrid Finite Element-Statistical Energy Analysis)法对设计的双层板样件进行隔声量计算并通过实验验证。

Four representative double-layer boards are designed with reference to the structure and size of the doublelayer board of the car body.The influence of the double-layer structure of the body on the sound transmission loss of the double-layer board is analyzed by comparing the sound insulation curves of the design schemes.The results show that increasing the thickness of the double-layer board has a limited effect on the sound insulation of the double-layer board,but increasing the clearance between the two layers of the board can control the critical frequency of the double-layer board and move it to the low frequency side.Thus,the sound transmission loss of the target frequency band is raised.In addition,increasing the bending protrusion on the surface of the double-layer board can change the mode,and thus significantly change the sound insulation performance of each frequency band of the double-layer board.Finally,the hybrid FE-SEA method is used to calculate the sound insulations of the designed double-layer board samples and the results are verified by experiments.