Influence of Damping Layer’s Thickness on Vibration Damping Performance of Structures

The finite element method based on modal strain energy(MSE) theory was selected for analysis.Firstly,the accuracy of MSE was verified,and it was found that the mean errors of the first five natural frequencies and modal loss factors were only 0.020 and 0.112,respectively.Then,using damping layer thickness as a variable,the dynamic behaviors of two typical passive structures — free damping structure and constrained damping structure were analyzed.The results show that with damping layer thickness increasing from 0.2mm to 1.5mm,the first five natural frequencies of the two kinds of structures were all reduced,the loss factors were all raised.Mutual comparison of the two kinds of structures shows that the vibration reduction performance of the free damping structure is more dependent on damping layer thickness,namely,the vibration damping characteristic of the constrained damping structure with a thin damping layer thickness is obviously superior to that of the free damping structure.