Damping characteristics of cylindrical sandwich shell with metal-rubber under high temperature condition

Abstract:

In order to identify the damping and vibratio-reduction characteristics of metallic cylindrical sandwich shell under high temperature condition, a metal-rubber material with excellent temperature resistance and viscoelastic damping characteristics was adopted as the sandwich core for damping layer. The effects of internal structural parameters and external excitation conditions on the dynamic mechanical characteristics of cylindrical sandwich shell with metal-rubber under different temperature gradients were studied. Firstly, the traditional metal-rubber stamping preparation process and vacuum brazing connection process were combined to realize the reliable metallurgical combination on the panel/core interface of sandwich cylindrical shell structural. The persistent temperature resistance of the prepared sample can be up to 500℃. Secondly, the effects of key parameters such as the core density, the thickness ratio of panel and core and the gradient temperature on the high-temperature damping characteristics by using different exiiation conditions were analyzed. The main performance evaluation indexes include the secant stiffness, the natural frequency, the vibration acceleration level and the high temperature damping ratio. Comparing to the non-sandwich cylindrical shell with equal quality, the stiffness of cylindrical sandwich shell with metal-rubber is positively correlated with the panel thickness and the core density. The damping effect decreases in the temperature range of 0-300℃, but increases in the temperature range of 300℃-500℃. The temperature-induced damping characteristic exhibits the obvious nonlinear.

Key words:Metal-rubber; Cylindrical sandwich shell; Brazing; Natural stiffness; Damping and vibration reduction