中文摘要：

以一端约束和一端自由的薄壁圆柱壳为研究对象,研究了约束层阻尼对其模态参数的影响。为了充分了解其振动行为特点,通过有限元法初步获取了其固有频率和模态振型,并搭建了可以准确、高效地测试涂覆约束层阻尼前、后壳体结构模态参数的实验系统,提出了适合该类型阻尼薄壳结构模态参数的测试方法和流程。将约束层阻尼材料制成不同大小的环片形式,并准确获得了涂覆约束层阻尼前、后薄壁圆柱壳的各阶模态参数。基于上述测试结果,研究了约束层阻尼参数的改变对薄壳固有频率、振型和阻尼参数的影响程度,发现约束层阻尼会降低结构的固有频率,但可以有效提升壳体结构的阻尼特性。

英文摘要：

The influence of constrained layer damping （CLD） on the modal parameters of thin cylindrical shell （TCS） is investigated. In order to fully understand the vibration characteristics of TCS, the natural frequencies and modal shapes of TCS are roughly obtained by finite element method. An experiment sy tem is established to measure the modal parameters of the shell with constrained layer with high accuracy and efficiency, and the corresponding test methods and procedures which are suitable for measuring the modal parameters of the shell with or without constrained layer are also proposed. CLD material is made into the annular slices with different sizes, and the modal parameters of TCS with or without constrained layer are accurately obtained. Based on the measured results, the influences of varied dimensional param- eters of such constrained layer on natural frequency, mode shape and damping of the shell structure are analyzed in details. It is discovered that CLD may reduce the natural frequency of TCS, but it can effec- tively improve its damping characteristics.