含弹性约束复合阻尼板的振动机理与特性

Vibration Mechanism and Characteristics of Composite Damping Plates with Elastic Constraints

针对汽车车身减振降噪需求,开发新型复合黏弹性阻尼材料。基于经典的自由阻尼和约束阻尼耗能原理,提出了一种含弹性约束的具有剪切和弯曲复合耗能机制的复合阻尼层结构。基于层间位移连续关系和薄板理论建立了阻尼复合板的位移方程和应变能能量方程,针对局部阻尼敷设及四边简支边界条件,结合假设模态法,推导出了复合阻尼板的运动微分方程、振动频率特征值方程等,求解得到了复合阻尼板的固有频率及损耗因子。复合阻尼层可用于研究单相材料不同参数特性及多相材料性能对比,且随着弹性层的上移,减振性能越好。复合耗能机理公式的推导,也为其在汽车上应用提供理论依据。

A new composite viscous damping material is developed to reduce the vibration and noise of car body.To analyze the mechanism of vibration and energy dissipation of the new type of viscous damping material on car body,the essay,based on the studies of the classic free damping layer and constrained layer damping,a composite damping layer with elastic constraints,composite shear,and its bending energy dissipation mechanisms is proposed..Based on the displacement continuous relations of layers and thin plate theory,the displacement and strain energy equationsare established.According tothe boundary conditions of local damping equipped and four edges simply supported,the composite damping plate motion differential equation and the eigenvalue equation of the vibration frequencyare deduced by combined with the assumption mode method.The natural frequency and the loss factor of the composite damping plate are also obtained.The composite damping layer can be used to study the different parameter characteristics of single-phase materials and the performance comparison of multiphase materials.In addition,the elastic layer moves up,the vibration damping performance is better.The derivation of the composite energy dissipation mechanism formula also provides a theoretical basis for its applications in automobiles.