金属橡胶夹芯柱壳结构高温阻尼减振特性

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

摘要:

针对金属夹芯柱壳结构在高温工况下的阻尼减振问题，提出采用具有优异耐温性能和粘弹性阻尼特性的金属橡胶材料作为夹芯阻尼层，研究内部结构参数和不同温度梯度对夹芯柱壳结构的动态力学特性影响规律。首先，采用传统金属橡胶冲压成型制备工艺，结合真空钎焊连接工艺，实现了夹芯柱壳结构面/芯界面可靠的冶金结合，可满足整体构件持续耐高温500℃以上。其次，分析了芯层密度、面芯厚度比、梯度温度等关键参数在不同激励条件下对金属橡胶夹芯柱壳结构高温阻尼减振特性的影响，主要性能评价指标包括：割线刚度、固有频率、振动加速度级及阻尼比等。通过与等质量的非夹芯柱壳结构试验对比表明：金属橡胶夹芯柱壳结构的刚度与面板厚度、芯层密度正相关；在0-300℃范围阻尼效果随温度下降，但在300℃-500℃范围内呈上升趋势，高温阻尼减振特性表现出显著的温致非线性。

关键词:金属橡胶;夹芯柱壳;钎焊;割线刚度;阻尼减振

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