弹性支承黏弹性阻尼-航空发动机薄壁机匣动力学特性分析

面向航空发动机薄壁机匣部件黏弹性约束层阻尼减振分析的工程需求,开展黏弹性阻尼-机匣弹性支承边界模拟和结构动力学分析研究。将机匣进行力学简化为圆柱壳体模型,通过引入一系列人工弹簧,将圆柱壳边界载荷的转化为弹簧的弹性势能,实现了机匣任意边界支撑刚度的有效模拟。结果表明：增大边界刚度可以提高机匣的固有频率,机匣的阻尼特性对支承刚度的敏感性与固有频率相反。此外,在机匣工程设计过程中,可以通过加强支撑结构的环向和法向刚度,获得满意的结构动力学特性。

Dynamic characteristics analysis of aero engine casing structures with viscoelastic damping materials under elastic supports

The analysis approach of the casing with viscoelastic damping material treatment under arbitrary elastic supports was proposed for the requirement of the vibration control of aero engine casing. The casing was considered as a thin-wall cylindrical shell. Then the governing dynamic equation of casing treated with the constrained layer damping was established, in which the effects of shear stress due to viscoelastic damping material were considered. By introducing a series of boundary spring elements, the boundary load of the casing was transformed into the elastic potential energy of the spring, and the effective simulation of the arbitrary boundary support stiffness on the casing was realized. Results showed that the increasing boundary stiffness could improve the natural frequencies of the casing, while the sensitivity of the damping characteristics to the support stiffness was opposite to the natural frequencies. In addition, in the design process of engineering casing, the satisfactory structural dynamic characteristics can be obtained by strengthening the circumferential and normal stiffness of the supporting structure.