【摘要】 基于阻尼比的理论计算和试验测试,对黏性流体减振降噪机理进行了研究。针对等效薄板箱体,设计了不同黏性介质、不同油量和不同隔板距离双层板下的模态试验,得到了相应的阻尼特性。分析了黏性液体对结构振动噪声的影响规律,提出了改善结构阻尼特性的方法,并在双层油底壳的设计中得到了应用。试验结果表明:箱体流体量的增加、双层隔板及其隔板间油层的引入均能提高系统的阻尼比,降低系统的声辐射功率。更多还原

【Abstract】 Based on the theoretical calculation and measurement of damping ratio,the mechanism in reducing vibration and noise of viscous liquid was investigated.Aiming at the equivalent thin-wall box,the modal experiments which included different viscous medium,different liquid mass and double-layer plate with different inner plate’s distance were designed,and the corresponding damping ratios were gained.The rules of viscous liquid influence on structural vibration and noise were analyzed,the method which can improve the structural damping characteristic was presented and applied to the design of double-layer oil pan.The experimental results show that the increasement of box’s liquid mass and the introduction of double-layer plate and inner plate’s oil layer can enhance the damping ratio of system,and reduce the power of acoustic radiation.更多还原